Dmitry Vysochinskiy

• Baral, Sushmita; Lande, Ingrid & Vysochinskiy, Dmitry (2026). Opportunities and challenges related to 3D printed concrete. Proceedings of the fib Symposium. 16(12), s. 4624–4633. doi: 10.3390/buildings16122300. Fulltekst i vitenarkiv Vis sammendrag

  Three-dimensional printed concrete (3DPC) has received growing attention as digital fabrication technologies continue to influence construction workflows. This study presents a systematic review of research published between 2015 and 2026, following PRISMA guidelines. Based on the reviewed literature, six opportunity categories and six challenge categories were identified. The opportunities include design optimization, construction speed, materials innovation, labor reduction, remote area construction, and circular economy. The findings show that material innovation is the most extensively researched category; a substantial proportion of the literature focuses on materials, rheology, printability, and structural behavior, reflecting an emphasis on improving fresh-state properties, interlayer bonding, and mechanical performance. The second most researched opportunity is design optimization, followed by the circular economy. Research in the remaining three categories of construction speed, labor reduction, and remote area construction appears to be limited. The main challenges identified include reinforcement integration, structural performance, mixing and curing, high equipment costs, durability, and the lack of standards. High equipment costs and the lack of standards appear to be the least researched challenges, while the four remaining challenge categories are actively addressed by the research community.

• Fahimi, Pouya; Vysochinskiy, Dmitry & Khadyko, Mikhail Aleksandrovich (2026). A hybrid data-driven J2-based plasticity model for plastic anisotropy evolution in metals. Materials & design. ISSN 0264-1275. 271. doi: 10.1016/j.matdes.2026.117079. Fulltekst i vitenarkiv Vis sammendrag

  This study proposes a plasticity framework for describing anisotropic hardening and flow direction evolution, which employs data-driven concepts to enhance the traditional von Mises plasticity framework. The approach is an alternative to advanced anisotropic phenomenological plasticity models. On one hand, it incorporates all available data within the experimentally investigated loading path domain into the constitutive plastic response, unlike the traditional models which only use a limited part of the data. On the other hand, it defaults to standard isotropic J2 plastic flow outside of the investigated domain, without making unbased extrapolations of the plastic flow direction far into the untested loading paths. The hardening response is represented using an artificial neural network trained on stress–strain data obtained from different loading directions. Simultaneously, a plastic flow corrector reproduces the experimentally measured r-value evolution. The performance of proposed framework was assessed through finite element simulations of tensile specimens and compared against a conventional Voce hardening model calibrated using a single material orientation. The best agreement with experiments is achieved before the onset of necking, while larger deviations occur under the complex stress states that develop during post-necking deformation. The study demonstrates a thermodynamically admissible framework for modeling highly anisotropic plastic deformation.

• Fahimi, Pouya; Vysochinskiy, Dmitry & Khadyko, Mikhail Aleksandrovich (2026). A neural network-based hardening model for plastic anisotropy evolution in a face centered cubic material. Materials & design. ISSN 0264-1275. 267. doi: 10.1016/j.matdes.2026.116297. Fulltekst i vitenarkiv Vis sammendrag

  This study introduces a data-driven approach for modeling the complex anisotropic hardening behavior of polycrystalline materials, in which artificial neural network (ANN) is implemented as a surrogate work hardening function within a crystal plasticity (CP) framework. The common use of ANN in CP context is to bypass the high computational demand of CP and train the network on the CP simulation results, without challenging the underlying physics of CP models. The present study utilizes ANN in a different way, as a tool of mapping the still unknown domain of slip system interactions and improving the predictive capabilities of the CP models. A dataset of slips and hardening parameter combinations was extracted from crystal-level simulations calibrated to experimental data. Multiple ANN architectures were evaluated, with a network comprising 5 hidden layers identified as the most accurate for predicting the work hardening behavior on slip system level. The final model was implemented as a hardening rule in the CP model. The CP models with ANN work hardening function was compared to the conventional CP model. It outperformed the Voce hardening rule in predicting the anisotropic flow stress and work hardening rates for polycrystals, with stress prediction errors reduced to below 2%. The applicability and accuracy of the ANN-based function was also evaluated for the loading ranges and loading directions beyond the in-plane uniaxial tension used in the training dataset. Texture evolution and stress–strain curves were also analyzed across different material orientations for uniaxial and plane strain tension, demonstrating that the ANN-based function produced physically feasible results and was more accurate than the conventional Voce model even in the unseen territory. The proposed approach not only offers improved accuracy in predicting anisotropic flow stress, providing a viable alternative to traditional hardening functions in CP modeling. It also introduces a new methodology to analyze the experimental and numerical data in plasticity studies and highlights the potential of well-trained neural networks implemented in an appropriate physics-based framework to effectively capture the complex, non-linear hardening behavior of polycrystalline materials.

• Baral, Sushmita; Vetnes, Alexander Grødum; Lande, Ingrid & Vysochinskiy, Dmitry (2025). An experimental demonstration of the effect of cement reduction measures on the consistency of concrete. Proceedings of the fib Symposium. s. 78–87. Fulltekst i vitenarkiv
• Vysochinskiy, Dmitry & Lande, Ingrid (2025). An Experimental Study of Consistency and Strength Variation of 3D-Printed Concrete Mixes. I Kioumarsi, Mahdi & Shafei, Behrouz (Red.), The 1st International Conference on Net-Zero Built Environment: Innovations in Materials, Structures, and Management Practices. Springer. ISSN 9783031696268. doi: 10.1007/978-3-031-69626-8. Fulltekst i vitenarkiv Vis sammendrag

  Concrete three-dimensional (3D) printing technology has the potential to significantly reduce on-site labour activities, as 3D-printed concrete eliminates the need for formwork. However, challenges persist in ensuring the quality and strength of 3D-printed concrete. One of the factors likely to impact its strength is the fluctuation of the water-to-binder ratio (w/b) during the printing process. In contrast to traditional cast-in-place concrete, where the mix is prepared at the factory with a fixed water-to-binder ratio, 3D-printed concrete is continuously mixed from a dry mix during printing. The amount of water added to the dry mix is routinely adjusted by the printer operator to maintain optimal consistency. This adjustment affects the water-to-binder ratio, leading to variations in concrete strength. This chapter investigates the extent to which the consistency and strength of 3D-printed mortar may vary while remaining printable using an industrial-scale concrete printer. Using the same dry mix, we observed a difference of approximately 15% in the mean strength for samples cast at the 3D printing site on two different dates. Additionally, there was about a 20% difference in the strength between the thickest and thinnest printable consistencies mixed in the laboratory. This variation must be considered when determining the design strength of 3D-printed concrete.

• Vysochinskiy, Dmitry & Moe, Ole-Bjørn Ellingsen (2024). On the scalability of strength and presumed size effects in SLM-produced 316L stainless steel. I Araujo, Anna Carla; Cantarel, Arthur; Chabert, France; Korycki, Adrian; Olivier, Philippe & Schmidt, Fabrice (Red.), Material Forming – ESAFORM 2024. Materials Research Forum LLC. ISSN 9781644903131. s. 60–69. doi: 10.21741/9781644903131-7. Fulltekst i vitenarkiv
• Fahimi, Pouya; Vysochinskiy, Dmitry & Khadyko, Mikhail Aleksandrovich (2024). An experimental study of effect of printed thickness on the mechanical properties of LPBF produced AlSi10Mg. I Araujo, Anna Carla; Cantarel, Arthur; Chabert, France; Korycki, Adrian; Olivier, Philippe & Schmidt, Fabrice (Red.), Material Forming – ESAFORM 2024. Materials Research Forum LLC. ISSN 9781644903131. s. 137–145. doi: 10.21741/9781644903131-15. Fulltekst i vitenarkiv Vis sammendrag

  Additive manufacturing process allows fabrication of parts with a broad range of sizes with high resolution. This size variation introduces new mechanical properties within the printed component, which creates a significant challenge for the qualification of additively manufactured parts. This unresolved issue hinders the implementation of additive manufacturing in high performance engineering applications. To attain optimal performance of additive components, it is imperative to gain a comprehensive understanding of the size effect. While many studies have explored the mechanical properties and microstructure of additively manufactured AlSi10Mg, the size effect remains relatively undefined. To gain more knowledge on this matter, AlSi10Mg samples with four different thicknesses were fabricated using a selective laser melting machine and tensile tests were performed to characterize the material behavior. Stress-strain curves were derived with consideration of nominal and measured cross section and the resulting diagram showed a considerable difference for the samples with minimum thickness, which was 0.5 mm. Comparing the results between the 2 mm and 0.5 mm thick specimens demonstrated more than 50 percent decrease in tensile properties including ultimate tensile strength and elongation at fracture. Also, the study of strain rate indicated no significant strain rate sensitivity for either thickness. These findings contribute to better understanding the size effects on behavior of printed AlSi10Mg, promoting further commercial adoption of this material.

• Noorsumar, Gulshan; Rogovchenko, Svitlana; Robbersmyr, Kjell Gunnar; Vysochinskiy, Dmitry & Klausen, Andreas (2023). Development and Extended Validation of a Lumped Parameter Prediction Model for Analysing Injury Parameters in a Vehicle Crash. I Wagner, Gerd; Werner, Frank; Tuncer, Oren & Rango, Floriano De (Red.), Simulation and Modeling Methodologies, Technologies and Applications. SIMULTECH 2021. Springer. ISSN 9783031231490. doi: 10.1007/978-3-031-23149-0_1. Fulltekst i vitenarkiv
• Noorsumar, Gulshan; Rogovchenko, Svitlana; Vysochinskiy, Dmitry & Robbersmyr, Kjell Gunnar (2023). A Numerical Comparison of Lagrange and Kane’s Method for Modeling and Crashworthiness Assessment of a Modified Vehicle. I Wagner, Gerd; Werner, Frank & Rango, Floriano De (Red.), Simulation and Modeling Methodologies, Technologies and Applications. SIMULTECH 2022. Springer. ISSN 9783031438233. s. 156–176. doi: 10.1007/978-3-031-43824-0_9. Fulltekst i vitenarkiv
• Vysochinskiy, Dmitry & Akhtar, Naureen (2022). On the Influence of Cross-Section Size on Measured Strength of SLM-Produced AlSi10Mg-Alloy. Key Engineering Materials. ISSN 1013-9826. 926, s. 132–140. doi: 10.4028/p-g078sc. Fulltekst i vitenarkiv Vis sammendrag

  The freedom in choice of geometries in additive manufacturing (AM) favors the use of structures with large surface and small cross-section such as lattice structures and thin-walled hollow profiles. On the other hand, the practices of strength testing of metals require a certain bulk of the material to be printed to be able to produce a sample and test material properties. The size of the sample cross section might influence the strength and up to 30% decrease in strength for small struts was reported in the literature. Understanding the influence of the cross-section size on the strength of SLM-produced metal is crucial to be able to relate the strength determined through tensile testing and the strength of an SLM-produced component with complex geometry. This article deals with effect of cross-section size on the measured strength of the SLM-produced AlSi10Mg-alloy. It is demonstrated how the decrease in strength can be explained by the difference between measured and actual cross-section area induced by surface roughness rather than by the difference in microstructure between the samples of different sizes.

• Noorsumar, Gulshan; Rogovchenko, Svitlana; Robbersmyr, Kjell Gunnar & Vysochinskiy, Dmitry (2022). Vehicle crashworthiness performance in frontal impact: Mathematical model using elastic pendulum. Mechanics research communications. ISSN 0093-6413. 124. doi: 10.1016/j.mechrescom.2022.103954. Fulltekst i vitenarkiv Vis sammendrag

  Vehicle occupant injuries due to collisions cause many fatalities every year. Safe vehicle design plays a critical role in averting serious injuries to occupants and vulnerable road users in the event of a crash. In this paper we study a full frontal vehicle crash against a rigid barrier introducing a Lumped Parameter Model (LPM) inspired by the elastic pendulum motion. The model uses polar coordinates to simplify the problem and the governing equations have been defined using Lagrangian formulation. The Simulink model has been validated against Finite Element (FE) data demonstrating good correlation with pitching angle and maximum crush of the vehicle. These parameters are crucial for designing vehicles which efficiently protect occupants.

• Noorsumar, Gulshan; Rogovchenko, Svitlana; Vysochinskiy, Dmitry & Robbersmyr, Kjell Gunnar (2022). Modeling of Modified Vehicle Crashworthiness using a Double Compound Pendulum. I Wagner, Gerd; Werner, Frank & Rango, Floriano De (Red.), Proceedings of the 12th International Conference on Simulation and Modeling Methodologies, Technologies and Applications. SciTePress. ISSN 9789897585784. s. 102–111. doi: 10.5220/0011306100003274. Fulltekst i vitenarkiv Vis sammendrag

  Vehicle crash modeling has been a challenge for researchers for several decades. Occupant injury prevention and prediction is a critical area within vehicle safety design. The modeling of material failure in structural members during a full frontal crash has been presented in this paper. This study presents a Lumped Parameter Model (LPM) with an elastic double compound pendulum replicating the impact kinematics. The model defined using Lagrangian formulation; presents a novel methodology to represent material fracture caused due to heat affected zones or welding in Ultra High Strength Steels (UHSS) in a non-linear crash event. The material fracture leads to rotation of the vehicle; presented in the form of torsional springs in the LPM developed in this study. The Simulink model has been validated with a finite element simulation and shows good correlation to predict parameters crucial to design for occupant protection in a vehicle crash.

• Noorsumar, Gulshan; Robbersmyr, Kjell Gunnar; Rogovchenko, Svitlana & Vysochinskiy, Dmitry (2022). An Overview of Data Based Predictive Modeling Techniques Used in Analysis of Vehicle Crash Severity. I Sanfilippo, Filippo; Granmo, Ole-Christoffer; Yayilgan, Sule Yildirim & Bajwa, Imran Sarwar (Red.), Intelligent Technologies and Applications: 4th International Conference, INTAP 2021, Grimstad, Norway, October 11–13, 2021, Revised Selected Papers. Springer. ISSN 9783031105241. s. 355–379. doi: 10.1007/978-3-031-10525-8_28. Fulltekst i vitenarkiv Vis sammendrag

  Accident injury prediction is a crucial constituent to reducing fatalities linked to vehicle crashes. The vehicle development process and road safety planning includes also the injury prediction for occupants and Vulnerable Road Users (VRUs) in a vehicle crash and the identification of the factors responsible for increased traffic collision injuries. This paper reviews the different data-based prediction techniques to modeling a vehicle crash event, crash frequency and crash severity. Machine learning (ML) is a research field which has gained impetus in the recent years and is widely used in different engineering applications; including injury prediction in vehicle collisions. The paper is divided into two major sections; the first section presents an overview of the existing predictive models for estimating injury severity in a crash event to occupants and VRUs and the second section describes the applications of data-based modeling techniques to predict crash frequency in different traffic scenarios. We also discuss possible future applications of data-based modeling techniques in this domain.

• Mahdavipour, Mohammad Ali & Vysochinskiy, Dmitry (2022). Micromechanical Modeling of Corroded Steel Joints under Excessive Plastic Deformations. Journal of performance of constructed facilities. ISSN 0887-3828. 36(2). doi: 10.1061/(ASCE)CF.1943-5509.0001706. Fulltekst i vitenarkiv Vis sammendrag

  Under excessive plastic deformations, pitting corrosion can accelerate ductile fracture initiation in steel structures. For an accurate numerical prediction of ductile fracture in corrosion pits, a micromechanical fracture criterion along with a fine three-dimensional solid meshing is required. Previous studies on this topic are limited to simple plates; however, for a more detailed component, e.g., steel beam-to-column joint, implementing the pit geometry on the global model of the joint is challenging in terms of meshing and computational time. In this paper, two-level numerical modeling was employed to reduce the complexity of the problem. In this technique, submodels with refined mesh are used to perform micromechanical simulations and assess the ductility degradation of joints. For a case study joint, the pits near the edge of the web and flange plates were found to be the most critical and they can reduce the fracture initiation displacement of the joint by about 25%. On the other hand, the pits located on the edges of plates or far from the edges caused a negligible reduction in the fracture initiation displacement of the joint. These results suggest two-level numerical modeling as a viable technique to facilitate micromechanical simulation of pitting corrosion in corroded steel joints.

• Mahdavipour, Mohammad Ali & Vysochinskiy, Dmitry (2022). Developing Fracture-Based Fragility Curves for Steel Components in Corrosive Environments. Journal of Structural Engineering. ISSN 0733-9445. 148(4). doi: 10.1061/(ASCE)ST.1943-541X.0003299. Fulltekst i vitenarkiv Vis sammendrag

  Under excessive plastic deformations, pitting corrosion accelerates ductile fracture initiation in steel components. Because of the stochastic and time-dependent nature of corrosion in steel material, the integrity of the steel components must be evaluated through a rational procedure in which corrosion uncertainties are considered to estimate the probability of failure for future events. Previous studies developed fragility curves to predict the capacity of global structures under uniform corrosion. However, for steel structures subjected to pitting corrosion, the local effect of corrosion is substantial and is also challenging to implement in the global model of structures. In this study, the concept of fracture-based fragility curves was developed at the component level by micromechanical modeling of different random pitting morphologies at a given intensity level of pitting corrosion. For this purpose, a unique meshing technique was employed to implement random pitting morphologies in numerical models. A demonstration study on a single-sided corroded plate revealed that random morphologies at an identical corrosion intensity level led to a notable dispersion in the failure elongations. The proposed fragility curves could address this effect on the probability of failure of the specimen. Therefore, decision-makers can reliably utilize such curves in a comprehensive risk-based corrosion management framework to evaluate the risk of failures and determine proper treatment strategies.

• Noorsumar, Gulshan; Vysochinskiy, Dmitry; Englund, Even; Robbersmyr, Kjell Gunnar & Rogovchenko, Svitlana (2021). Effect of welding and heat treatment on the properties of UHSS used in automotive industry. The European Physical Journal Conferences. ISSN 2101-6275. 250. doi: 10.1051/epjconf/202125005015. Fulltekst i vitenarkiv Vis sammendrag

  This paper deals with the undesired effects of the heat treatments on the mechanical properties of (UHSS) Ultra High Strength Steel used nowadays in automotive industry to improve crashworthiness performance of vehicles. The UHSS specimens were extracted from certain parts of the car body and subjected to different heat treatments. Four types of specimens were tested: untreated, welded with metal inert gas welding, heat treated at 800 °C, and heat treated at 1250 °C. All heat-treated specimens showed dramatically reduced values of strength. The results suggest that it is important to follow the official repair manuals avoiding unnecessary welding and improper heat treatments of UHSS. The experiments provide the data necessary for constructing a constitutive model and performing a finite-element analysis of improperly repaired UHSS parts.

• Noorsumar, Gulshan; Rogovchenko, Svitlana; Robbersmyr, Kjell Gunnar & Vysochinskiy, Dmitry (2021). Mathematical models for assessment of vehicle crashworthiness: a review. International Journal of Crashworthiness. ISSN 1358-8265. 27(5). doi: 10.1080/13588265.2021.1929760. Fulltekst i vitenarkiv Vis sammendrag

  This article reviews approaches to mathematical modeling of a vehicle crash. The growing focus on vehicle and occupant safety in car crashes has triggered the need to study vehicle crashworthiness in the initial stages of vehicle development. The major motivation for this work is to support vehicle crashworthiness design during the product development process.The article is divided into two parts; the first one overviews existing mathematical models used to solve engineering problems. The second part describes modeling strategies applied for replicating non-linear vehicle crash event and occupant kinematics in an occupant protection loadcase. We also highlight alternative modeling strategies using hybrid modeling techniques aimed at the improvement of the vehicle development process.

• Noorsumar, Gulshan; Rogovchenko, Svitlana; Robbersmyr, Kjell Gunnar; Vysochinskiy, Dmitry & Klausen, Andreas (2021). A Novel Technique for Modeling Vehicle Crash using Lumped Parameter Models, 11th International Conference on Simulation and Modeling Methodologies, Technologies and Applications (SIMULTECH 2021). SciTePress. ISSN 9789897585289. s. 62–70. doi: 10.5220/0010529200620070. Fulltekst i vitenarkiv Vis sammendrag

  This paper presents a novel technique for modeling a full frontal vehicle crash. The crash event is divided into two phases; the first until maximum crush and the second part when the vehicle starts pitching forward. This novel technique will help develop a three degrees of freedom (DOF) lumped parameter model (LPM) for crash and support in the vehicle development process. The paper also highlights the design process for reducing vehicle pitching in occupant protection load cases. The model has been validated against a finite element (FE) simulation of a full frontal crash of a Chevrolet Silverado developed by the National Highway Traffic Safety Administration (NHTSA), and the LPM shows good correlation with the FE test data.

• Vysochinskiy, Dmitry; Akhtar, Naureen; Nordmo, Tord; Strand, Mathias Rabjerg; Vyssios, Adrian & Bak, Morten Kollerup (2021). Experimental investigation of effect of printing direction and surface roughness on the mechanical properties of AlSi10Mg-alloy produced by selective laser melting. ESAFORM 2021. ISSN 2198-9915. doi: 10.25518/esaform21.3627. Fulltekst i vitenarkiv Vis sammendrag

  The additive manufacturing has initially gained popularity for production of non-loadbearing parts and components or in the fields where the material strength and ductility are less important such as modelling and rapid prototyping. But as the technology develops, availability of metal additive manufacturing naturally dictates the desire to use the produced components in load-bearing parts. This requires not-only a thorough documentation on the mechanical properties but also additional and independent research to learn the expected level of variation of the mechanical properties and what factors affect them. The presented paper investigates strength, ductility, hardness, and microstructure of the AlSi10Mg alloy produced by the selective laser melting (SLM). The mechanical properties were determined through a series of uniaxial tension tests and supplementary hardness tests and rationalized with the microstructure evolution with regard to printing direction and heat treatment. The paper also addresses the effect of surface roughness on the mechanical properties of the material, by comparing the machined and net shape tension samples. As expected, the as-manufactured AlSi10Mg-alloy appears to be a semi-brittle alloy, but its microstructure can be altered, and ductility increased by a proper heat-treatment. The effect of surface layer removal on the measured mechanical properties is of particular interest.

• Mahdavipour, Mohammad Ali & Vysochinskiy, Dmitry (2020). Effect of the Joint Strength on the Performance of Ordinary Moment-resisting Frames Under a Progressive Collapse Situation. I Papadrakakis, M.; Fragiadakis, Michalis & Papadimitriou, C. (Red.), EURODYN 2020: Proceedings of the XI International Conference on Structural Dynamics. European Association for Structural Dynamics. ISSN 9786188507227. s. 3995–4006. doi: 10.47964/1120.9327.19341. Fulltekst i vitenarkiv
• Noorsumar, Gulshan; Robbersmyr, Kjell Gunnar; Rogovchenko, Svitlana & Vysochinskiy, Dmitry (2020). Crash Response of a Repaired Vehicle-Influence of Welding UHSS Members. SAE technical paper series. ISSN 0148-7191. 1- 2020(April), s. 1–5. doi: 10.4271/2020-01-0197. Fulltekst i vitenarkiv Vis sammendrag

  Automakers generally recommend not to weld structural parts after a vehicle crash, and these should be replaced as a whole part in case of a crash event. Sectioning of these members is also not recommended and use of the repair manual is mandatory in case of fracture of such parts. However, repair shops may not adhere to these instructions and use incorrect repair procedures on these members which would modify their strength properties. This study analyses the impact of welding structural members in a vehicle like the A-pillar which use Ultra-High Strength Steels (UHSS) for reducing the weight of the vehicle and improving the crashworthiness of the structure. The research conducted in this paper highlights the differences in the crash performance of a repaired vehicle as opposed to baseline injury values for the vehicle. The performance of the modified vehicle when tested for different loadcases shows reduced crash performance as compared to the baseline performance and it can be concluded that welding or sectioning the UHSS parts would influence the crashworthiness of a vehicle. This paper only focuses on structural integrity of the repaired vehicle in a crash event. The performance of the vehicle in occupant injury is kept out of scope for this study.

• Vysochinskiy, Dmitry & Rybakov, Dmitri (2020). On the Effect of Various Heat Treatments on Microstructure of AISI 4130 Steel Used in Sour Service Pipes, ASME 2020 39th International Conference on Ocean, Offshore and Arctic Engineering - Volume 3: Materials Technology. The American Society of Mechanical Engineers (ASME). ISSN 9780791884348. doi: 10.1115/OMAE2020-18017. Fulltekst i vitenarkiv
• Stave, Daniel Årrestad; Schlanbusch, Rune; Vysochinskiy, Dmitry & Grasmo, Geir (2019). Condition Monitoring of Steel Wire Ropes. I Dohm, M. A. R. (Red.), Exploring Opportunities - Synthetic/Steel - Proceedings of the OIPEEC Conference 2019. OIPEEC. ISSN 9781733600408. Fulltekst i vitenarkiv
• Mahdavipour, Mohammad Ali; Ding, songxiong & Vysochinskiy, Dmitry (2019). Performance of welded flange plate joints between steel beams and box columns without continuity plates. I Zingoni, Alphose (Red.), Advances in Engineering Materials, Structures and Systems: Innovations, Mechanics and Applications. CRC Press. ISSN 9780429426506. s. 1179–1183. Fulltekst i vitenarkiv
• Munyazikwiye, Bernard; Vysochinskiy, Dmitry; Kdadyko, Mikhail & Robbersmyr, Kjell Gunnar (2018). Prediction of Vehicle Crashworthiness Parameters Using Piecewise Lumped Parameters and Finite Element Models. Designs. 2(4). doi: 10.3390/designs2040043. Fulltekst i vitenarkiv Vis sammendrag

  Estimating the vehicle crashworthiness experimentally is expensive and time-consuming. For these reasons, different modelling approaches are utilised to predict the vehicle behaviour and reduce the need for full-scale crash testing. The earlier numerical methods used for vehicle crashworthiness analysis were based on the use of lumped parameters models (LPM), a combination of masses and nonlinear springs interconnected in various configurations. Nowadays, the explicit nonlinear finite element analysis (FEA) is probably the most widely recognised modelling technique. Although informative, finite element models (FEM) of vehicle crash are expensive both in terms of man-hours put into assembling the model and related computational costs. A simpler analytical tool for preliminary analysis of vehicle crashworthiness could greatly assist the modelling and save time. In this paper, the authors investigate whether a simple piecewise LPM can serve as such a tool. The model is first calibrated at an impact velocity of 56 km/h. After the calibration, the LPM is applied to a range of velocities (40, 48, 64 and 72 km/h) and the crashworthiness parameters such as the acceleration severity index (ASI) and the maximum dynamic crush are calculated. The predictions for crashworthiness parameters from the LPM are then compared with the same predictions from the FEA.

• Vysochinskiy, Dmitry; Coudert, Térence; Hopperstad, Odd Sture; Lademo, Odd-Geir & Reyes, Aase Gavina Roberg (2017). Experimental study on the formability of AA6016 sheets pre-strained by rolling. International Journal of Material Forming. ISSN 1960-6206. s. 1–17. doi: 10.1007/s12289-017-1363-6. Fulltekst i vitenarkiv Vis sammendrag

  The effects of prestrain by rolling on the formability of AA6016 sheets in the biaxial stretching region are studied in this paper. An experimental program including formability experiments has been carried out for as-received and prestrained sheets. Forming limit strains are determined by the digital image correlation technique and then mapped into stress space using an anisotropic plasticity model in order to assess the pathindependence of forming limit stresses. Different diagrams for description of formability such as the traditional strain-based forming limit diagram (FLD), the forming limit stress diagram (FLSD) and various equivalent plastic strain based (EPS-based) diagrams are applied in order to study the effect of prestrain. It is shown that prestrain by rolling has the same effect on the forming limit strains as prestrain by plane strain tension. Furthermore, the forming limits of the virgin material nearly coincide with the forming limits of the prestrained material in the FLSD and EPS-based diagrams, serving as a conservative estimate for the prestrained material. Due to the roping phenomenon, the material displays significant anisotropy in forming limit strains. At the same time, the presence of roping does not affect the path-independence of the forming limits in the FLSD and EPS-based diagrams.

• Vysochinskiy, Dmitry; Coudert, Térence; Hopperstad, Odd Sture; Lademo, Odd-Geir & Reyes, Aase Gavina Roberg (2016). Experimental detection of forming limit strains on samples with multiple local necks. Journal of Materials Processing Technology. ISSN 0924-0136. 227, s. 216–226. doi: 10.1016/j.jmatprotec.2015.08.019. Fulltekst i vitenarkiv Vis sammendrag

  Sheet metal formability is traditionally described by the forming limit curve (FLC). Experimental FLCs are obtained by performing formability tests and determining failure strains. The strains are usually measured either by etching a grid on the sheet surface or by digital image correlation (DIC). Ductile metal sheets fail primarily by local necking which introduces a severe strain gradient in the failure region. This makes accurate detection of the failure strains challenging. An international standard (ISO12004-2:2008) was introduced in 2008 to unify the procedure of FLC detection; prior to this large discrepancies were observed between the results reported by different laboratories. The main limitation of the standard method for detection of forming limits is that its application is limited to cases where a single local neck is formed in the metal sheet prior to fracture. In the case of multiple local necks, the samples are simply discarded. Furthermore, the standard method does not include any guidelines to distinguish the failure by local necking and direct failure by fracture. One of the advantages of DIC over the traditional etched-grid technique is that the former allows us to obtain not only the strain distribution but also its history. This allows for alternative methods for detection of forming limit strains. This paper introduces a DIC-based method which was specially developed to handle the case of multiple local necks and to distinguish failure by local necking from direct fracture automatically. The method is not confined to a single test type and can be used in combination with different formability tests as long as DIC is used to measure strains.

• Vysochinskiy, Dmitry; Coudert, Térence; Hopperstad, Odd Sture; Lademo, Odd-Geir & Reyes, Aase Gavina Roberg (2014). Experimental detection of the onset of local necking in an aluminium sheet. Materials Science Forum. ISSN 0255-5476. 794-796, s. 590–595. doi: 10.4028/www.scientific.net/MSF.794-796.590. Fulltekst i vitenarkiv Vis sammendrag

  Forming limit diagrams (FLDs) are widely used to assess metal sheet formability. Experimental FLDs are obtained by performing formability tests and determining failure strains. The standard method for detection of forming limits is based on the spatial distribution of the strains and requires formation of a single local neck. Some aluminium alloys, such as AA6016, have a tendency to form multiple strain localizations in formability tests, which can be interpreted as multiple local necks. Thus, use of the standard method is questionable for these aluminium alloys. The present paper presents an alternative, digital-image-correlation-based method for experimental detection of the onset of local necking in an aluminium sheet. The method is based on monitoring the sheet-thickness evolution, and is developed to be user independent and resistant to noise in the measurements. The method can be used in combination with different types of formability tests. The main requirement is that digital image correlation is used for strain measurements. Here, the method is initially tested on uniaxial tension tests of AA6016 aluminium alloy sheets and then extended to formability tests.

• Gruben, Gaute; Vysochinskiy, Dmitry; Coudert, Térence; Reyes, Aase Gavina Roberg & Lademo, Odd-Geir (2013). Determination of Ductile Fracture Parameters of a Dual-Phase Steel by Optical Measurements. Strain. ISSN 0039-2103. 49(3), s. 221–232. doi: 10.1111/str.12030. Fulltekst i vitenarkiv Vis sammendrag

  Marciniak–Kuczynski and Nakajima tests of the dual-phase steel Docol 600DL (www.ssab.com/) have been carried out for a range of stress-states spanning from uniaxial tension to equi-biaxial tension. The deformation histories of the specimens have been recorded by digital images, and the displacement and strain fields have been determined by post-processing the images with digital image correlation software. The fracture characteristics of the material are presented by means of the stress triaxiality, the Lode parameter and the equivalent strain. These parameters are evaluated on the surface of the specimens based on the optical field measurements and assumptions regarding the mechanical behaviour of the material. Additionally the minor versus major principal strains up to fracture are presented. It is found that the material displays a significantly lower ductility in plane-strain tension than in uniaxial tension and equi-biaxial tension, and that it, in the tests exposed to local necking, undergoes large strains between the onset of necking and fracture. Fractographs of selected specimens reveal that fracture is due to growth and coalescence of voids that occur in localised areas governed by shear-band instability.

• Vysochinskiy, Dmitry; Coudert, Térence; Reyes, Aase Gavina Roberg & Lademo, Odd-Geir (2012). Determination of forming limit strains using Marciniak-Kuczynski tests and automated digital image correlation procedures. Key Engineering Materials. ISSN 1013-9826. 504-506, s. 17–22. doi: 10.4028/www.scientific.net/KEM.504-506.17. Fulltekst i vitenarkiv Vis sammendrag

  Forming limit strains are used to construct a forming limit diagram (FLD), which is a diagram in the principal strain space, traditionally used for designing forming operations of sheet metals. A line indicating the boundary between safe and unsafe strains is often called the forming limit curve (FLC). FLDs are also used to evaluate results from finite element simulations. Therefore consistency and reproducibility are important. This paper deals with the experimental determination of forming limit strains from Marciniak-Kuczynski (MK) tests. The material tested is AA6016 aluminum alloy in three different conditions: virgin material and material subjected to 5% and 8% deformation by rolling. Strains were measured by the use of digital image correlation (DIC) technique. Forming limit strains were determined by the use of two automated methods. The results from the two methods are compared and evaluated regarding their applicability to the Marciniak-Kuczynski test and ability to capture actual forming limit strains.

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• Noorsumar, Gulshan; Rogovchenko, Svitlana; Robbersmyr, Kjell Gunnar; Vysochinskiy, Dmitry & Klausen, Andreas (2021). A Novel Technique for Modeling Vehicle Crash using Lumped Parameter Models. Fulltekst i vitenarkiv
• Noorsumar, Gulshan; Robbersmyr, Kjell Gunnar; Rogovchenko, Svitlana & Vysochinskiy, Dmitry (2021). An overview of Data Based Predictive Modeling Techniques used in Analysis of Vehicle Crash Severity. Fulltekst i vitenarkiv
• Noorsumar, Gulshan; Rogovchenko, Svitlana; Robbersmyr, Kjell Gunnar & Vysochinskiy, Dmitry (2023). Modeling, Simulation and Prediction of Vehicle Crashworthiness in Full Frontal Impact. Universitetet i Agder. ISSN 9788284271132. Fulltekst i vitenarkiv Vis sammendrag

  Vehicle crashworthiness assessment is critical to help reduce road accident fatalities and ensure safer vehicles for road users. Techniques to assess crashworthiness include physical tests and mathematical modeling and simulation of crash events, the latter is preferred as mathematical modeling is generally cheaper to perform in comparison with physical testing. The most common mathematical modeling technique used for crashworthiness assessment is nonlinear Finite Element (FE) modeling. However, a problem with the use of Finite Element Model (FEM) for crashworthiness assessment is inaccessibility to individual researchers, public bodies, small universities and engineering companies due to need for detailed CAD data, software licence costs along with high computational demands. This thesis investigates modeling strategies which are affordable, computationally and labour inexpensive, and could be used by the above-mentioned groups. Use of Lumped Parameter Models (LPM) capable of capturing vehicle parameters contributing to vehicle crashworthiness has been proposed as an alternative to adopting FEM, while the later have been used to validate LPMs developed in this thesis. The main crash scenario analysed is a full frontal impact against a rigid barrier. Front-end deformation which can be used to measure crash energy absorption and pitching which could lead to occupant injuries in a frontal crash event are parameters focused on. The thesis investigates two types of vehicles; vehicle with initial structure intact is defined as baseline vehicle, while a vehicle that underwent unprofessional repairs on its structural members made of Ultra High Strength Steel (UHSS) is defined as a modified vehicle. The proposed novel LPM for a baseline vehicle impact is inspired by pendulum motion and expresses the system using Lagrangian formulation to predict the two phases of impact: front-end deformation and vehicle pitching. Changes in crashworthiness performance of a modified vehicle were investigated with a FEM; tensile tests on UHSS coupons were conducted to generate material inputs for this FEM. Further, a full scale crash test was conducted to validate the FE simulations. An LPM to conduct crashworthiness assessment of a modified vehicle has been proposed, it is based on a double pendulum with a torsional spring representing the vehicle undergoing a full frontal impact.

• Mahdavipour, Mohammad Ali; Vysochinskiy, Dmitry & Jiang, Zhiyu (2022). Failure prediction of steel components under the coupled effect of excessive plastic deformations and pitting corrosion. Universitetet i Agder. ISSN 9788284270739. Fulltekst i vitenarkiv Vis sammendrag

  Nowadays, modern computers have made advanced computational resources accessible to analysts engaged in the field of structural engineering. Through these advancements, the role of numerical modeling has increasingly become more significant in both research and engineering projects. In addition, improved testing facilities and measuring instruments like digital image correlation (DIC) have made material testing more informative than before, and engineers can calibrate more complicated material models to simulate complex phenomena such as plasticity and fracture. All developed testing and numerical modeling techniques come together to form a numerical failure assessment framework for steel structures. Due to the distinct advantages of numerical modeling over full-scale testing, this framework is welldeveloped in many applications (e.g., elastic analyses). However, in many other applications, numerous involved phenomena and their interactions with each other, as well as additional factors (e.g., corrosion), call for more development both in material testing and numerical techniques to customize the framework to better suit the final application. This thesis has focused on the failure assessment of steel components under the coupled effect of extensive plasticity and pitting corrosion. A framework was developed based on experimental material calibration and stochastic numerical modeling approaches.

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