Residual Plastic Deformation Research Articles

Dual skin effect and deep heterostructure of titanium alloy subjected to high-frequency electropulsing-assisted laser shock peening

Laser shock peening, an advanced technology for severe surface plasticity peening, encounters challenges such as shallow hardened layers and surface spalling when dealing with difficult-to-machine materials. In this study, we introduced a high-frequency electropulsing-assisted laser shock peening (HFEP-LSP) technique that coupled laser shock peening with high-frequency electric pulses to achieve a significant and deeper plastic deformation layer. In the HFEP-LSP technique, we first considered the dual “skin effect”, which coupled the skin effect of high-frequency electric pulses with the “skin effect” of the mechanical effect induced by the laser shock wave. An integrated experimental platform comprising an electric pulse generator, laser shock peening equipment, and a control system was built. A >1.6 mm deep compressive residual stress layer was obtained, and the depth of the plastic deformation layer increased by 83.3 %. Furthermore, we elucidated the dual “skin effect”-induced complex heterostructure and βm phase transition. A comprehensive analysis revealed the factors contributing to the deeper strengthening layer induced by HFEP-LSP, including the compressive residual stress and plastic deformation layers. In addition, the effects of laser shock peening and HFEP-LSP on the mechanical properties were investigated. Compared to the annealed samples, the ultimate tensile strength and elongation of the HFEP-LSP-treated samples were increased by 12.3 % and 57.1 %, respectively, with a fatigue life improvement of 176.4 %. The mechanism of synergistic improvement in strength and ductility was demonstrated.

Elastoplastic properties of ion exchangers based on cross-linked polyelectrolytes

In this paper, we dilatometrically studied the elastoplastic properties of spherical grains of industrial weakly acidic and strongly acidic ion-exchanger in experiments with constant uniaxial compression and a subsequent unload at room temperature, depending on the ionic form and concentration of the electrolyte solution. It was found that the ionic form of polyacrylate and polymethacrylate cross-linked with triethylene glycol dimethacrylate and divinylbenzene, respectively, and the concentration of the external solution affects their elastoplastic properties. In dilute solutions of sodium chloride and calcium chloride, the gels exhibited elastic properties with close relative amplitudes of deformation. The amplitude of deformation of the grain of polymethacrylate crosslinked with divinylbenzene, in the Ni form, in a dilute nickel chloride solution was significantly lower than that of the Ca form, with significant plastic deformation. With an increasing concentration of the external solution of calcium and nickel chlorides under mechanical load on the grain of polymethacrylate cross-linked with divinylbenzene, the total deformation of the granule and the magnitude of elastic deformation decreased, while the residual (plastic) deformations increased. In concentrated solutions of CaCl2 and NiCl2, such an ion-exchanger became an inelastic rigid material. Even under increased mechanical load, the magnitude of its elastic compressive deformation was very small. The K-form of a swollen in water strongly acidic polystyrene cation-exchanger with grafted sulpho groups cross-linked with divinylbenzene is also characterized by elastic deformations, i.e. the polymer is in a highly elastic state. However, the polystyrene matrix is more rigid compared to polyacrylic and polymethacrylic cation-exchangers in the alkali metal ion form, so the amplitude of deformation is significantly smaller. For such a cation-exchanger in Ca- and Ni- forms, elastic deformations prevail even in concentrated solutions.

Limpet-inspired design and 3D/4D printing of sustainable sandwich panels: Pioneering supreme resiliency, recoverability and repairability

Sandwich panels, characterized by their solid exterior and thick, soft core, find extensive applications ranging from maritime to aerospace sectors due to their exceptional resilience and energy absorption/dissipation capabilities. The natural limpet, known for its resilience to mechanical loading, serves as inspiration in the present research to introduce innovative repairable core shells. Limpet-inspired shells with elasto-plastic and brittle behaviors are designed and 3D/4D printed using polylactic acid (PLA) filaments and resins via fused filament fabrication (FFF) and liquid crystal display (LCD) techniques. While PLA filament exhibits an elasto-plastic response with a shape-recovery feature, the resin results in brittle structures for LCD-printed design. The study demonstrates that the FFF-printed PLA shell can fully recover residual plastic deformations, while the LCD-printed PLA shell exhibits a mechanical fracture behavior very similar to the natural limpet with brittle properties. A nonlinear finite element model (FEM) is also developed to replicate the large deformations of the samples under quasi-static compression with a high level of accuracy. Experimental and numerical results reveal that the samples with material, mechanical behavior, and geometry close to the natural limpet result in the maximum energy dissipation per unit mass. Two bio-inspired cores are then tessellated to introduce a new class of sustainable sandwich panels with supreme recoverability, resiliency, and repairability. A three-point bending test is numerically carried out on sandwich panels using FEM, and their energy absorption and dissipation capacities are studied. Results demonstrate that the proposed sandwich panels can achieve almost 7.33 and 1.17 times higher energy dissipation per unit mass than those developed based on a recycled thermoplastic bottle cap core. This pioneering research sets a new benchmark for structural design in terms of resiliency, recoverability, repairability, and sustainability.

Investigating fretting wear mechanisms in Ti-6Al-4V: insights from residual stress and equivalent plastic strain analysis

Purpose The study delves into the influence of wear cycles on these parameters. The purpose of this paper is to identify characteristic patterns of σRS and εPEEQ that discern varying wear situations, thereby contributing to the enrichment of wear theory. Furthermore, the findings serve as a foundational basis for nondestructive and in situ wear detection methodologies, such as nonlinear ultrasonic detection, known for its sensitivity to σRS and εPEEQ. Design/methodology/approach This paper elucidates the wear mechanism through the lens of residual stress (σRS) and plastic deformation within distinct fretting regimes, using a two-dimensional cylindrical/flat contact model. It specifically explores the impact of the displacement amplitude and cycles on the distribution of residual stress and equivalent plastic strain (εPEEQ) in both gross slip regime and partial slip regimes. Findings Therefore, when surface observation of wear is challenging, detecting the σRS trend at the center/edge, region width and εPEEQ distribution, as well as the maximum σRS distribution along the depth, proves effective in distinguishing wear situations (partial or gross slip regimes). However, discerning wear situations based on εPEEQ along the depth direction remains challenging. Moreover, in the gross slip regime, using σRS distribution or εPEEQ along the width direction rather than the depth direction can effectively provide feedback on cycles and wear range. Originality/value This work introduces a novel perspective for investigating wear theory through the distribution of residual stress (σRS) and equivalent plastic strain (εPEEQ). It presents a feasible detection theory for wear situations using nondestructive and in situ methods, such as nonlinear ultrasonic detection, which is sensitive to σRS and εPEEQ. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2024-0005/

Machine learning-based characterization of friction stir welding in aluminum alloys

This research presents a machine learning (ML) approach that integrates Bayesian theorem to predict residual stress, plastic deformation, and peak temperature in friction stir welding (FSW) of different types of aluminum alloys. The training data was acquired from extensive numerical simulations of FSW conducted across various input parameter configurations. The regression analysis exhibits strong predictive performance for residual stress, peak temperature, and plastic deformation, achieving determination coefficients of 0.969, 0.955, and 0.919, respectively. The high prediction performance of the developed model is primarily attributed to Bayesian optimization, distinguishing it from other conventional ML methods. The results further demonstrate the efficacy of the proposed model in assessing the relevance of input features to prediction efficiency and output targets. For instance, concerning processing parameters, the predictive performance is closely correlated with the significance of preheating, traverse speed, and rotational speed in FSW, compared to welding force and plate thickness. On the other hand, considering material properties, it was observed that the hardness value of aluminum alloys emerged as a crucial predictor in the model so that alloys with moderate hardness values showed greater welding consistency and significantly enhanced prediction accuracy.

Artificial neural network and ANFIS approaches for mechanical properties prediction and optimization of a turbine blade treated by laser shock peening

This research article covers a comprehensive investigation on the prediction and optimization of residual stresses, plastic deformations and damage induced by laser shock peening (LSP) on a thin Ti-6Al-4 V leading edge sample of a turbine blade. The study is based on a two-part approach: the first part involves a numerical simulation of the LSP process and the characterization of its effects on the material. The finite element analysis (FEA) is used to simulate the complex interactions between laser parameters, material properties and mechanical response. This numerical analysis generates valuable insights into the residual stress distribution, the plastic deformation and the potential damage within the sample being treated. Based on the numerical results, the second part highlights the novel application of the artificial neural network (ANN) and the adaptive neuro-fuzzy inference system (ANFIS) methods. By taking advantage of the strength of ANN and ANFIS, the models are able to learn accurately from all the data generated by numerical simulations, allowing them to precisely predict and optimize the effects induced by LSP: residual stresses, plastic strains and damage. This paper provides a significant contribution to the field of materials science and engineering, by offering an in-depth comprehension of the LSP process impact on Ti-6Al-4 V leading-edge turbine blade specimens. The combined utilization of numerical analysis and artificial intelligence AI-driven techniques offers a comprehensive approach to optimize the LSP process, leading to the fatigue resistance improvement and service life extension of turbine blades and other critical aerospace components. The proven capability of ANN and ANFIS enables innovative solutions in aerospace engineering and surface treatment technologies, promoting the AI implementation in materials processing and design.

Thermal expansion behavior and analysis of Al/AlN interpenetrating phase composites with different preform porosity

In this work, the coefficient of thermal expansion (CTE) of Al/AlN interpenetrating phase composites (IPCs) has been measured based on the length change from room temperature (RT) to 200 °C. 3D representative volume elements (RVEs) are created to model the microstructures of Al/AlN IPCs and the finite element models generated from RVEs are used to study thermal expansion behavior. CTE was predicted utilizing the finite element method (FEM) and thermo-elastic models of Kerner, Turner and Schapery, after which the results were compared with the experimental values. According to experimental results, a notable reduction in the CTE of IPCs is observed as preform porosity decreases. This shows that an AlN preform can effectively enhance dimensional stability. A comparative analysis of extant literature indicates that IPCs may attain a lower CTE compared to particle-reinforced composites. Experimental data align closely with analytical models. The FE simulation results demonstrate better consistency with experimental data only under conditions of high preform porosity, since residual thermal stresses and plastic deformation were not considered.

Influence of plasticity on the magnetic-field-induced bending deformation in a magneto-active elastomer with superparamagnetic nanoparticles

The influence of residual plastic deformation on the bending deformation of a magnetoactive elastomer (MAE) beam with non-coercive superparamagnetic manganite (La0.6Ag0.2Mn1.2O3) nanoparticles induced by a transverse uniform magnetic field has been studied. It was found that the MAE bending induced by the magnetic field switching-on/switching-off is mainly cyclic elastic. Plastic deformation leads to the emergence of residual bending and hysteresis in the field dependence of the bending. It was shown that the residual bending that appears after the first magnetic field switch-on eliminates the uncertainty of the bending direction at the next magnetization. Due to the residual plastic deformation, the bending direction of the superparamagnetic MAE with nanoparticles does not change when the direction of the applied magnetic field is inverted, in contrast to the MAE with microparticles where the uncertainty of the bending direction is eliminated due to the residual magnetization of weakly coercive ferromagnetic microparticles; therefore, the bending direction changes its sign with magnetic field reversion. In the low fields, the bending value for the MAEs with superparamagnetic particles is proportional to the square of the magnetic field strength. Model estimates on the residual deformation influence on the beam bending at beam magnetization reversal were obtained.

ЧИСЛОВЕ МОДЕЛЮВАННЯ НАПРУЖЕНО-ДЕФОРМОВАНОГО СТАНУ ПРИ АДИТИВНОМУ MIG НАПЛАВЛЕННІ КРЕМНІЄВОЮ БРОНЗОЮ CuSi3Mn1

The article analyzes in detail the stress-strain state during additive manufacturing using silicon bronze CuSi3Mn1 (БрКМц3-1), which is widely used in the machine-building industry for the manufacture of bushings, spring parts, and parts of chemical apparatus. The high cost of non-ferrous copper-based alloys makes it important to use Welding Arc Additive Manufacturing (WAAM) technologies. The processes of layer-by-layer surfacing of silicon bronzes lead to residual stresses at the tensile strength of the material, which can eventually provoke the development of critical defects in the form of cracks. Based on the simultaneous solution of the finite element method for the equations of heat balance and mechanics of a solid deformed body, the peculiarities of temperature distribution and parameters of the stress-strain state for the developed model of a triangular equilateral prism, which is additively generated from CuSi3Mn1 bronze, are determined. Verification of the experimental model with the calculated one was carried out by comparing the thermal cycles of surfacing. Based on the anal-ysis of the results of numerical modeling, it was found that the nature of the temperature change and the magnitude of its decrease in the corresponding layer after the deposition of subsequent layers are the same and do not depend on the deposition trajectory, and the largest residual equivalent plastic deformations are formed in the first layer with a gradual decrease inthe value in each subsequent deposited layer, which is associated with a decrease in the degree of volume of the VAT prism from the 1st to the 10th layer. The lower layers are characterized by a volumetric stress state due to the presence of rigid binders in the form of the substrate and the upper welded layers, which increases the probability of cracking in these layers during the cooling stage due to a decrease in the material's strength below σB< 170 MPa in the temperature range of 475-550 °C

Development of crystallographic misorientation in laser powder bed fusion 316L stainless steel

This study examines the development of crystallographic misorientation and its relations to the solidification microstructure in Laser Powder Bed Fusion (LPBF) alloys. We performed a single laser track experiment on an SS316L single-crystal substrate to characterize the correlation between solidification features and misorientation evolution within a single LPBF melt pool and found that the sources of misorientations inside the melt pool can be attributed to both rapid solidification (misorientation aligning precisely with the cell walls & colony boundaries) and residual stress-induced plastic deformation (misorientation independent of solidification morphology), while the residual stress-induced plastic deformation acts as the sole mechanism to extend this misorientation outside of the melt pool boundary. The misorientation development both inside and outside of the melt pool always occurs through a crystal rotation around one of the {111} axes without any obvious correlation with the sample orientations. Additionally, we conducted a comprehensive literature overview of mechanisms in the solidification process and critically assessed the current understanding of misorientation formation and the causes of the loss of epitaxial grain growth.

The roles of residual martensite and plastic deformation in thermomechanically coupled functional degradation of nanocrystalline superelastic NiTi alloys

Residual martensite and plastic deformation are the culprits of functional degradation in NiTi alloys. However, their roles in thermomechanically coupled functional degradation of nanocrystalline superelastic NiTi alloys have not been investigated systematically and quantitatively. In this paper, the origins of thermomechanically coupled functional degradation of nanocrystalline superelastic NiTi alloys are subdivided into (i) plastic deformation including dislocation slipping in nanocrystals and shearing of amorphous phase, (ii) Type A residual martensite (RMA) originating from the incomplete reverse transformation during non-isothermal deformation, and (iii) Type B residual martensite (RMB) stabilized by the internal stress owing to inconsistent plastic strains among neighboring grains. For the first time, the inverse relation between fRMA and strain rate in NiTi with GS of 6 nm (a crystalline-amorphous nanocomposite) is determined experimentally. We find that the residual strain is mainly caused by plastic deformation except when RMA accumulates drastically. It is substantiated that plastic deformation lowers both forward and reverse transformation stresses significantly. Residual martensite plays an important role in the decrement of forward transformation stress, while has little impact on reverse transformation stress.

Elasto-plastic analysis and optimal design of composite integral abutment bridge extended with limited residual plastic deformation

Due to the growing significance of structural theories concerning the composite structure analysed and designed plastically, this paper introduces a new optimisation method for controlling the plastic behaviour of a full-scale composite integral abutment bridge by employing complementary strain energy of residual forces that existed within the reinforcing rebars. Composite bridges are structures made of components such as steel and concrete, which are frequent and cost-effective building methods. Thus, various objective functions were used in this work when applying optimum elasto-plastic analysing and designing the composite integrated bridge structure that was tested experimentally in the laboratory. In contrast, the plastic deformations were constrained by restricting the complementary strain energy of the residual internal forces aiming to find the maximum applied load and the minimum number of steel bars used to reinforce the concrete column part of the structure. The numerical model employed in this paper was validated and calibrated using experimental results, which were considered inside ABAQUS to produce the validated numerical model, using concrete damage plasticity (CDP) constitutive model and concrete data from laboratory testing to solve the nonlinear programming code provided by the authors. This paper presents a novel optimization method using complementary strain energy to control the plastic behaviour of a full-scale composite integral abutment bridge, with the original contribution being the incorporation of residual forces within reinforcing rebars to limit plastic deformations. Following that, a parametric investigation of the various optimisation problems revealed how models performed variously under different complementary strain energy values, which influenced the general behaviour of the structure as it transitioned from elastic to elasto-plastic to plastic; also results showed how the complementary strain energy value is connected with the amount of damaged accrued in both concrete and steel.

Optimal Elasto-Plastic Analysis of Prestressed Concrete Beams by Applying Residual Plastic Deformation Limitations

This work introduces elasto-plastic analysis of prestressed reinforced concrete beams under different prestressing conditions by limiting the residual plastic behaviour inside the steel bars using complementary strain energy. A non-linear optimal method was used to limit residual plastic deformations in steel bars, including prestressed tendons, used to reinforce beams from two previous research investigations. This was considered by using an optimization approach with an objective function to find the maximum loading while applying constraints on the complementary strain energy of residual internal forces in steel elements to control residual plastic deformations. Thus, an elasto-plastic optimization programme was linked to models simulated by ABAQUS, as concrete was calibrated by the concrete damage plasticity (CDP) model. Some variables were considered regarding the force applied inside prestressed tendons and the number of tendons used inside the models. Thus, limits on complementary strain energy affected load values and model damage where an increase in the permissible strain energy value leads to an increase in the corresponding loading values produced; thus, this produces a higher stress intensity in steel and tension-damaged areas in concrete. Based on these data, many comparisons have been made to determine when beams behaved elastically and how they turned into plastic.

Numerical study of rock-breaking mechanism in hard rock with full PDC bit model in compound impact drilling

Geothermal reservoir rocks have the characteristics of high stress, high hardness and high abrasiveness, which makes the drilling rate low and the drilling cost high, and hinders the application of geothermal energy. Improving drilling efficiency in hard rock strata is the prerequisite for large-scale application of geothermal energy. Impact drilling is considered to be the most effective drilling method in hard formations. PDC (Polycrystalline diamond Compact) bit compound impact drilling is one of the impact drilling methods, which has been widely concerned in recent years. In order to further improve the drilling efficiency of this method, the mechanism of PDC bit compound impact rock breaking is studied. Drucker–Prager criterion was used as rock constitutive relation, equivalent plastic strain was used as rock failure criterion, MSE (mechanical special energy) was used as evaluation method of rock-breaking efficiency, and a three-dimensional simulation model of full-size PDC bit for compound impact rock-breaking was built. The rock breaking law in PDC bit compound rock breaking process and the impact vector angle and impact duration on rock breaking efficiency are analyzed. The results show that the compound impact drilling can effectively alleviate the stick–slip vibration phenomenon, and improve drilling efficiency. In the compound impact mode, compressive stress failure and tensile stress failure occur at the same time, and the tensile stress failure is the main failure mode. The peak stress of the rock is 5.49% larger, and the residual plastic deformation is about 4.28% smaller than that of non-impact mode. With the increase of impact angle, the MSE decreases first and then increases a little. The optimal impact vector angle is in the range of 30°–50°. With the increase of the impact time, the MSE decreases in a wavy manner. In the range of 0.2 ms–1.0 ms, the optimal impact time is 0.8 ms–1.0 ms.

Analysis of the effects of isothermal aging and Laser Shock Peening on the flow properties, fatigue crack growth, and fracture toughness of Inconel 718

Laser Shock Peening (LSP) is a surface treatment that improves the fatigue life and fatigue strength of components by inducing a shallow layer that is characterized by compressive residual stress and plastic deformation. This study investigates the use of LSP on Inconel 718 (IN718) on the fatigue crack growth (FCG) and fracture toughness (FT) of as-received (AR), solution-treated (SOL), and samples aged for 0.5, 4, and 100 h. Experimental results on aged samples established that the hardness of samples 0.5 and 4 h increased due to the precipitation of γ′ and γ″ phases while in the 100 h sample the hardness decreases due to the presence of coarser γ″ phase and intergranular δ-phase. These microstructural features impacted the plastic flow behavior of the different samples which was adequately described using a two-fitting approach to the Voce equation. While thermal aging accelerated the FCG of aged samples, the plastic flow and residual stress induced by the LSP significantly reduces the effect of thermal aging, by reducing the FCG rate and increasing the FT of the IN718 aged samples. Finally, results from EBSD analysis showed that the LSP-induced plastic strain depends on the microstructural transformations that occurred during the aging treatment.

Optimal Elasto-Plastic Analysis of Reinforced Concrete Structures under Residual Plastic Deformation Limitations

Optimal Elasto-Plastic Analysis of Reinforced Concrete Structures under Residual Plastic Deformation Limitations

Cyclic Behavior and Modeling of Reinforced Concrete Shear Walls Based on Enhanced Bond-Based Peridynamics

Peridynamics (PD) has gained increasing usage in simulating the nonlinear damage behavior of reinforced concrete (RC) structures due to its extraordinary capacity in solving discontinuous problems. This paper presents an enhanced bond-based peridynamic (BPD) modeling method for simulating the complex nonlinear behavior of RC shear walls, such as strength deterioration and cracking propagation, under cyclic loading conditions. In the proposed BPD method, a novel concrete bond model is presented that can consider the stiffness degradation, strength deterioration, and residual plastic deformation. A steel model and a coupled axial-shear model are adopted to simulate the nonlinear behavior of rebar and reinforcement-concrete interaction. The enhanced PD is implemented in an open-source finite element software framework, OpenSees, and can perform implicit or explicit, dynamic or static analyses in a parallel manner. Two RC shear walls under cyclic loading conditions are used as verification examples. The nonlinear damage behavior is studied in detail for the RC shear walls, e.g. the strength deterioration, pinch effect, and cracking behavior. The results demonstrate that the enhanced BPD modeling approach is capable of simulating the nonlinear damage behavior of RC shear walls under cyclic loading conditions.

Water jet impact damage mechanism and dynamic penetration energy absorption of 2A12 aluminum alloy

This study aims to explore the waterjet cavitation impact (WCI) mechanism of 2A12 aluminum alloy and its dynamic penetration energy absorption after WCI treatment. The effects of WCI process parameters on the residual stress, surface quality, and microstructure of 2A12 aluminum alloy are investigated through experiment and simulation and, a dynamic penetration model of 2A12 aluminum alloy is established with ABAQUS software and finite element simulation is performed. The results show that WCI can greatly enhance the residual compressive stress of the target. Comprehensive evaluation of surface residual stress, surface quality, and plastic deformation layer reveals that a combination of small jet angle with large jet pressure, or large jet angle with medium jet pressure, delivers the best strengthening effect; the residual compressive stress and plastic deformation layer introduced by WCI can effectively increase the defensible performance of 2A12 aluminum alloy, making the projectile residual velocity far lower than before WCI treatment.

Plastic hexahedral FEM for surgical simulation.

Soft-tissue manipulations, such as collecting, stretching or tearing tissue, are a common component of surgery. When too much force is applied, these manipulations result in a residual plastic deformation that surgeons should be aware of and that should be modeled by surgical simulation. Many tissues, vessels and organs can be modeled as offsets of curved simple shapes with primary directions, e.g., radial and axial for cylinders yield a rectangular mesh whose normal offset naturally yields a hexahedral mesh that can serve as a thick shell. Other organs are easy to embed into and deform following a hex mesh. We extend existing code for the volumetric finite element method (FEM) to model tissue plasticity as hexahedral thick shells or embedded organs. Specifically, the work extends the open source Simulation Open Framework Architecture and its newest hyperelastic deformation addition, Caribou, with focus on surgical simulation. The extension factors deformation gradients into (corotational or hyperelastic) elastic factors and plastic factors and enforces volume preservation. Limits on per-element twist, twist torque, material hardening and bounds on plasticity where elements invert avoid the need for re-meshing. Our hexahedral FEM avoids the biased outcomes of asymmetric coarsely-partitioned tetrahedral FEM. Caribou's hyperelastic FEM is extended to hex-FEM stretching plasticity. Our high-order accurate blended-vertex deformation enables coarse hex meshes to model large plastic rotational and stretch deformations without re-meshing. We compare a vertex-blended to a cell-centered piecewise constant approach; contrast plasticity based on corotational FEM and hyperelastic FEM; and test the computation under mesh refinement. The volume is preserved also for large deformations. On-the-fly generated hexahedral meshes can directly be used as finite element domains for plastic deformation based on corotational or hyperelastic elasticity. The outcome is suitable for surgical simulation.

The Behavior of a 3D Printed Panel under Thermal Stress

AbstractPLA‐based panels are widely used in many applications. Sometimes these panels can be subjected to uneven heating processes of their various areas. As the cooling process also has a nonuniform character, the appearance of residual stresses of thermal nature is expected, which can lead to the appearance of residual plastic deformations of the panel. Finite element modeling and images taken with the help of an infrared camera confirm the process of uneven panel heating under the action of heat generated by an infrared radiation lamp. The models made using the finite element method concluded that deviations are possible in the form of a concavity in that area of ​​the panel surface located closer to the heat source and in the form of convexity on the opposite surface. The experimental results obtained on polylactic acid panels with thicknesses of 2 and 4 mm confirm the generation by uneven cooling of shape deviations with sizes up to 3.39 mm.