Dynamic Impact Response Research Articles

Impact Dynamic Response of Spherical Net Shells: Finite Element-Based Computational Analysis Investigating the Influence of Dynamic Constitutive Models

The net shell is a widely utilized large-span space structure known for its aesthetically pleasing design and uniform load distribution, as well as serving as a prominent architectural landmark. In recent years, the impact resistance research of mesh and shell structures has garnered increased attention due to the accumulation of local conflicts. In this study, a parametric model of the spherical mesh shell was developed with Rhino software, and a numerical analysis model for a K8 mesh shell was established through the application of the ABAQUS finite element analysis software. Subsequently, the proposed numerical analysis method for the impact test was applied to validate its accuracy. The research also explored various dynamic constitutive models, such as Cowper-Symonds, Johnson-Cook, modified temperature term Johnson-Cook, and modified strain term and temperature term Johnson-Cook, with the assessment of their impact on the numerical simulation of impact resistance. Based on the impact dynamic response of the spherical net shell of different materials, the selection of an appropriate dynamic constitutive model for the numerical simulation of impact resistance in the spherical net shell was the MJ-C model. The comparative analysis of different materials, including Q235B, Q355B, Q460D, and 6061-T6, indicated that when the impact material failed to penetrate the structure instantly, the improvement of the material strength would enhance the impact resistance of the structure. On the other hand, when the impact material managed to penetrate the structure instantly, the material strength would not significantly help mitigate the damage. Notably, brittle materials, such as aluminum alloy, exhibited a distinct absence of a pronounced yield stage compared with low-carbon steel, which ultimately led to a relatively abrupt deformation.

A Numerical Study of Complex Impact Loads on Thin-Walled Casing of Aeroengine Considering Turbine Guide Vane Structure1

As the main load-bearing component of the aero-engine system, the thin-walled casings have the characteristics of large size, complex structure, thin wall, and large area. In addition to the harsh working environment, it is necessary to study applicable preventive measures to contain high-energy fragments to ensure flight safety. The complex load formed by the axial impact and circumferential torsion exerted by the turbine rotor on the exhaust casing is studied, and the model includes the turbine rotor. By analyzing the deformation and energy dissipation of the exhaust casing in the calculation results, the dynamic response of the power turbine and the exhaust casing in the complex impact load is obtained, and it is verified that the initial speed of the power turbine has no obvious relationship with the dynamic response and energy dissipation of the exhaust casing. At the same time, it is concluded that the axial velocity and aerodynamic force of the power turbine have a strong positive correlation with the complex impact load and dynamic response of the exhaust casing. In the follow-up studies and equivalent experiments, these conclusions can be used as a reference for further experimental design.

Axial Compression Performance of Reinforced Concrete Columns after Lateral Impact Load

Axial compression performance and bearing capacity of reinforced concrete column is crucial to concrete structure. Lateral Impact load could pose severe danger to the security and service life of reinforced concrete column. Impact dynamic response, axial compression performance and residual bearing capacity of reinforced concrete columns after lateral impact load were investigated in this paper. Investigation results indicated that with the increase of impact energy, residual displacement and crack width on column increased, impact damage on column exacerbated. It was proved that impact resistance performance of reinforced concrete column could be enhanced by preload axial force. Residual bearing capacity of reinforced concrete column degenerated obviously after subjected to lateral impact load. And RC column would be under elastic stage when impact energy was low. According to analysis results on the correlation between residual displacement and residual bearing capacity, prediction model on residual bearing capacity of reinforced concrete column after lateral impact load was proposed.

Construction of Collision Equivalent Scaled Model for Locomotive Using Multi-Parameter Nondimensional Method

At present, the research on crashworthiness of locomotive mainly adopts the method of theoretical analysis, numerical simulation and component test, it is too expensive and less repeatable to carry out vehicle crash tests. Therefore, a method to construct the collision equivalent scaled model (SM) for locomotive based on multi-parameter nondimensional is presented in this paper. Firstly, an equivalent method of structural dynamic responses was proposed. The extraction process and analysis method of dynamic responses for thin plate structures widely existing in locomotives were studied. Then, according to the structural characteristics of the locomotive, the partition equivalent design was carried out, and a dimensionless analysis model of impact dynamic responses for SM was established. Finally, the SM crash test was carried out to verify the effectiveness of collision equivalent SM established, it was found that the SM has high reliability, it can achieve equivalence with the locomotive for energy absorption, average impact force, average acceleration of cab and center of gravity of vehicle body. Carrying out the SM crash test can study the reasonable configuration of energy absorption parameters for locomotives and obtain the impact dynamic responses of locomotives under different configurations of energy absorption parameters.

Experimental and numerical simulation study on failure mode transformation law of reinforced concrete beam under impact load

Changes in the primary influencing factors, such as structural configuration and impact energy, have an influence on the impact dynamic response and failure modes of reinforced concrete beams. In this paper, drop hammer impact tests with different reinforced concrete beam configurations and various impact conditions were conducted. Additionally, parameters of impact force, support force, reinforcement strain, concrete strain, impact local deformation and overall structural deformation were obtained by comprehensive measurements. On the dynamic response and failure modes of reinforced concrete beams, the effects of various concrete strengths, longitudinal/stirrup configurations, hammerhead shapes, and impact velocities were examined. LS-DYNA was applied to perform numerical simulations of reinforced concrete beams with various impact velocities, tensile longitudinal reinforcement ratios, and stirrup ratios. The result of the experiment proved that the peak displacement and residual displacement of reinforced concrete beams under low velocity impact increased with the improvement of impact velocity. Besides, the peak displacement and residual displacement were approximately linearly related to the ratio of impact kinetic energy to ultimate static bearing capacity. The higher the concrete strength and the greater the longitudinal reinforcement ratio were, the larger the peak impact force on the beam was under the equal impact conditions, whereas the smaller the overall displacement response was. The support force, midspan deflection, and residual deflection were less impacted by the form of the hammer head. However, the peak impact force was significantly influenced. Four failure modes of a beam under impact are assessed in accordance with the failure limit state of the structure: bending failure, bending-shear failure, shear failure, and punching failure. According to the test findings, with the improvement of impact velocity, the reinforced concrete beam went from bending failure to bending shear failure, shear failure, and punching failure under the same structural arrangement. By raising the concrete strength and stirrup ratio or lowering the longitudinal reinforcement ratio, the failure mode of the beam progressively changed from punching failure to bending failure while the impact velocity was the same. Through numerical simulation, it was found that the impact velocity of the falling hammer had the greatest influence on the failure mode of the reinforced concrete beam, followed by the ratio of the tensile longitudinal reinforcement, and the smallest was the stirrup ratio.

High-strength steel beams with hexagonal web openings under impact load

A drop-weight impact testing machine was used to conduct an impact test on 15 specimens in order to examine the impact resistance of high-strength (HS) steel beams with hexagonal web openings (SBHWO). The test findings demonstrate that as steel strength increases, maximal impact force and impact platform value rise, while maximum displacement, residual displacement, beam-end rotation, reduction ratio of opening area, and energy absorption ratio decrease. The use of high-strength steel can significantly improve the impact resistance of the SBHWO. When steel Q235 was lifted to steel Q550, the average increase of impact peak and impact platform value was 17.94% and 90.80%, respectively, and the average reduction range of maximum displacement and residual displacement in the span was 45.36% and 55.30%, respectively. After steel Q550 was upgraded to steel Q690, the improvement effect of impact resistance is small. Empirical equations of the relationship between impact energy，steel strength and dynamic responses were established.

Study on the Dynamic Response of Composite Box Girder Bridges with Corrugated Steel Webs

To more accurately consider the dynamic response of composite box girder bridges with corrugated steel webs under the effect of live loads, based on the theory of vehicle-bridge coupled vibration, a refined finite element model of vehicle-bridge coupled vibration analysis for composite box girders was established. The advanced dynamic response analysis of composite box girders with corrugated steel webs and traditional concrete box girders with 30 m single boxes and single cells, as well as with 50 m single boxes and multiple cells, was carried out. The research revealed that the natural vibration frequency of the composite box girder with corrugated steel webs is lower than that of the corresponding concrete box girder. When the bridge deck condition is poor, the dynamic impact coefficient of the composite box girder is much larger than that of the concrete box girder. When the bridge deck is in poor condition, the dynamic impact response is significantly enhanced, and the difference is significantly compared with that when the bridge deck is in good condition, which is greater than three times and even six times at the maximum. Both the difference in the vehicle model and the change in the vehicle speed influence the dynamic impact coefficient of the composite box girder.

Impact Dynamic Analysis of Suspended Marine Cables

Objective: It is often impossible to avoid collisions between marine cables, the impact dynamic response of the collisions between marine cable needs to be obtained. Methods: In this paper, we derive the lumped mass method based on the bending moment and torque; using the lumped parameter method, the suspended cable is discretized into lumped mass models, and the impact force of the suspended cable is considered in the dynamic analysis; the impact dynamics model of the suspension cable is developed by referring to the specific parameters of the suspension cable and combining them with offshore construction processes. Results: There is a relationship between the impact force and the tension of the cable. The tension and impact force are related in cable collisions. While the maximum effective tension occurs at the upper end of the vertical cable and at the collision point, the horizontal cable's tension at the collision position is minimal. The distribution of curvature mutates at the collision point, causing bending deformation. The horizontal cable experiences greater bending change at the collision position than the vertical cable. Conclusion: In summary, collision of different parts of vertical cable is not obvious, while horizontal cable is more prone to self-collision and collision with vertical cable. Collision impact on horizontal cable is greater, with minimum tension occurring at collision point. Maximum velocity for horizontal cable appears at collision position, and for vertical cable at bottom. Maximum acceleration for both cables occurs at collision zone.

Dynamic response and impact loads in twin-barge floatover installation

Complex impact loads during the floatover installation will threaten the mating operations. This paper presents the experimental investigation on the impact loads and dynamic response in the twin-barge floatover installation. In the model test, two critical loads transfer scenarios were modeled, including 0% and 100% stages in which the topsides are initially connected and separated from the barges. The near-zero gaps between the topsides and the twin-barge are simulated at two stages with the aim of investigating the collision characteristics. The impact loads on mating units, mooring forces, hawser forces, as well as motions of the twin-barge and the topsides were investigated. It is found that the windward barge motions are much larger than the leeward barge in sway, roll and yaw directions. The larger barge sway and yaw motions occurred at the 100% stage compared with the 0% stage. Statistical results indicate that the 100% stage seems to induce the larger impact loads on mating units than the 0% stage. The lateral impact loads were comparable with the vertical loads, in which the maximum lateral impact loads were even greater than the vertical impact loads. The mooring and hawser lines at the 100% stage are subjected to larger loads.

Nanocomposite Foams with Balanced Mechanical Properties and Energy Return from EVA and CNT for the Midsole of Sports Footwear Application

Polymer foam that provides good support with high energy return (low energy loss) is desirable for sport footwear to improve running performance. Ethylene-vinyl acetate copolymer (EVA) foam is commonly used in the midsole of running shoes. However, EVA foam exhibits low mechanical properties. Conventional mineral fillers are usually employed to improve EVA's mechanical performance, but the energy return is sacrificed. Here, we produced nanocomposite foams from EVA and multi-walled carbon nanotubes (CNT) using a chemical foaming process. Two kinds of CNT derived from the upcycling of commodity plastics were prepared through a catalytic chemical vapor deposition process and used as reinforcing and nucleating agents. Our results show that EVA foam incorporated with oxygenated CNT (O-CNT) demonstrated a more pronounced improvement of physical, mechanical, and dynamic impact response properties than acid-purified CNT (A-CNT). When CNT with weight percentage as low as 0.5 wt% was added to the nanocomposites, the physical properties, abrasion resistance, compressive strength, dynamic stiffness, and rebound performance of the EVA foams were improved significantly. Unlike the conventional EVA formulation filled with talc mineral fillers, the incorporation of CNT does not compromise the energy return of the EVA foam. From the long-cycle dynamic fatigue test, the CNT/EVA foam displays greater properties retention as compared to the talc/EVA foam. This work demonstrates a good balanced of mechanical-energy return properties of EVA nanocomposite foam with very low CNT content, which presents promising opportunities for lightweight-high rebound midsoles for running shoes.

Investigation of initial metallurgical factors on the dynamic impact response and adiabatic shear bands formation of the 6061 Al alloy

The effect of multi-pass friction stir processing and initial base metal condition on the dynamic impact response of AA6061-T6 alloy at high strain rates was investigated in this study. The Split-Hopkinson Pressure Bar (SHPB) was used in dynamic experiments with strain rates ranging from 1600 to 4200/s. The results revealed that the base metal alloy's (BM) dynamic flow stress was comparable to all the friction stir processed AA6061-T6 (FSP'd) specimens as the strain rate and true strain increased. The general increase in stress response levels as strain rates and true strain increases can be attributed to strain hardening. The higher values of strain rate sensitivity in multi-pass FSP'd specimens are an indication that they are more ductile in comparison to the BM condition. The optical and electron backscattered diffraction (EBSD) analysis showed that adiabatic shear bands were formed by heterogeneous deformation. The EBSD analysis revealed that the FSP'd specimens showed more abnormal grain growth and dynamic recrystallized sites than BM. The substantial decrease in dynamic flow stress, and high strain rate sensitive values of multi-pass FSP'd specimens compared to BM for all the investigated strain rates attributed to softening effect by dynamic recrystallization (DRX), and the emergence of abnormal grain growth during friction stir process.

Shaking table test study on dynamic performance of a base-isolated frame structure under an isolation bearing removal scenario

Studies on the progressive collapse of structures have been at the forefront in structural engineering domain recently. The progressive collapse of isolated structures is quite different from that of conventional fixed-base structures. Once an initial failure occurs in the isolation layer which is the most vulnerable to accidental events due to the low horizontal stiffness, progressive failures at other locations may lead to a large-scale collapse of isolated structures. This paper presents a 1:4 scale model shaking table test of a three-story irregular plane reinforced concrete (RC) frame isolated structure to investigate the progressive collapse resistance of isolated structures. An edge bearing was removed quickly by an electromagnetic failure excitation device during the first seismic input case. The dynamic responses such as the macroscopic crack distribution, acceleration responses, displacement responses, internal forces of the isolation bearings, and concrete and reinforcement strains of the failure span beams were evaluated. The results show that the significant vertical deformation with dynamic impact response was produced at the failure point under multi-directional dynamic coupling excitation, i.e., the combined effect of the vertical unbalanced load caused by sudden failure of a bearing and horizontal earthquakes. This sudden failure of the isolation bearing not only had an impact on the internal forces of bearings adjacent to the failure bearing, but also on other non-adjacent bearings. As the tensile and compressive stress of adjacent bearings were more likely to exceed design limits under earthquakes, the risk of overturning collapse for isolated structures markedly increased following the failure of a few bearings. In addition, vertical and low-frequency components of earthquakes could have a significant influence on dynamic responses and damages of isolated structures, especially in the area of bearing failure. The experimental results obtained in this study act as important references for the progressive collapse design of isolated structures.

Dynamic response characteristics of coral reef sand concrete under impact loading

The dynamic mechanical properties, energy evolution characteristics, breakage modes, and damage mechanism of coral reef sand concrete (CRSC) are distinctly different from those of land-sourced aggregate concrete. Because structures made of CRSC may suffer damage due to earthquakes and artillery shells, it is significant to investigate the impact resistance and dynamic response characteristics of CRSC. In this study, macroscopic and microscopic testing techniques were used to compare the dynamic response characteristics of CRSC, CRSC with polypropylene fibers (PFs), and CRSC with basalt fibers (BFs) under impact loading. The results showed that with increasing strain rate, the dynamic compressive strength and dynamic increase factor (DIF) of the CRSC increased via power and logarithmic functions, respectively. Furthermore, the PFs and BFs improved the dynamic compressive strength at medium and low strain rates. The damage modes of the CRSC and CRSC with BFs were primarily fragmentation damage, while the damage mode of the CRSC with PFs was core retention damage. The failure cracks of all three types of concrete developed through the coral coarse aggregate, cement mortar, and slurry near the interfacial bonds. Nanoindentation test results revealed the great bonding performances at the coral aggregate–slurry bond. The incorporation of PFs or BFs changed the form and content of the C–S–H in the interfacial transition zone of the CRSC, which in turn affected the mechanical properties of the CRSC. In practical engineering, however, PFs and BFs could still improve the seismic and blast-resistant performances of CRSC.

Parametrized non intrusive space-time approximation for explicit dynamic fem applications

In the following work, a benchmark of different non-intrusive model reduction approaches is performed on an explicit dynamic contact 3D-problem. The main purpose of this work is to evaluate the stability of the reduced model with respect to time along with the precision of these approaches with respect to the true solutions of interest. These solutions are the prediction of displacement and velocity fields. The precision of these approaches is also evaluated with respect to the evolution of some materials parameters. Six parameters vary in this study and we would like to predict the whole transient fast dynamic impact response with respect to each parameters. To this end, several models are trained : Proper Orthogonal Decomposition (POD) and Deep convolutional Neural Network (DcNN), in addition, a vectorized version of Interpolation in Grassman Manifolds is proposed. The benchmark performed illustrate that using DcNN’s allows to achieve the best precision and stability in predicting physical fields.

In-plane dynamic impact response and energy absorption of Miura-origami reentrant honeycombs

Honeycomb structures have attracted wide attention due to outstanding mechanical properties as promising light material structures. Inspired by nature and artistic design, various honeycombs with different microstructural configurations have been designed for the sake of better mechanical performances and functions. Here, the Miura-origami reentrant honeycomb (MRH) structure integrating reentrant honeycombs (RH) and Miura-origami structures is investigated systematically. Dynamic impact behaviors of the present MRH structure are investigated numerically. The deformation modes and energy absorption capacity of RH and MRH are compared under different impact velocities, including low-velocity, medium-velocity and high-velocity. The results show that the plateau stress and the specific energy absorption(SEA) of MRH is much higher than RH. Moreover, the parametric study indicates that raising the inclined angle will decrease the plateau stress and the absolute value of Poisson’ratio for MRH structures. The specific energy absorption curves increase as the inclined angle of MRH grows up. In addition, the MRH with smaller dihedral angle can absorb much more impact energy and the variation of absorbed energy is proportional to the cell wall thickness of the MRH structure. This work is expected to provide a new thought for designing advanced energy absorption metastructures and achieving superior mechanical performances.

Comparison of Energy Absorption Performance and Mechanical Response of Metal Fiber Porous Materials under Two Strain Rates

The relationship between dynamic impact response and pore structure of metal fiber porous materials is a frontier interdisciplinary science issue in the fields of materials and mechanics. Dynamic impact (strain rate of 800 s−1) and quasi-static compressive (strain rate of 10−3 s−1) behavior of stainless steel fiber porous materials (SSFPMs) are discussed and compared for different porosity levels and fiber diameters. Furthermore, the stress wave character during dynamic compression is also analyzed. Results indicate that the compressive properties and the plateau region of the stress–strain curve are affected significantly by porosity and strain rate; high strain rate or low porosity yields higher compressive strength, higher Young's modulus, and shorter plateau region. Moreover, SSFPMs with a porosity of 70% or less may be especially suitable for applying at the quasi-static compression condition to absorb energy completely. Besides, the optimum porosity or the allowable peak stress at a certain condition can be determined according to the energy absorption diagram of SSFPMs. Additionally, the stress wave propagated inside SSFPMs comprises three waves, the incident, the reflected, and the transmitted ones, independent of porosity and fiber diameter, and the propagation behavior of the stress wave is mainly influenced by porosity, not fiber diameter.

Investigation of dynamic impact responses of layered polymer-graphene nanocomposite films using coarse-grained molecular dynamics simulations

Polymer nanocomposite films have recently shown superior energy dissipation capability by using the micro-projectile impact testing method. However, how stress waves interact with nanointerfaces and the underlying deformation mechanisms have remained largely elusive. This paper investigates the detailed stress wave propagation process and dynamic failure mechanisms of layered poly(methyl methacrylate) (PMMA)-graphene nanocomposite films during piston impact through coarse-grained molecular dynamics simulations. The spatiotemporal contours of stress and local density clearly demonstrate shock front, reflected wave, and release wave. By plotting shock front velocity (Us) against piston velocity (Up), we find that the linear Hugoniot Us−Up relationship generally observed for bulk polymer systems also applies to the layered nanocomposite system. When the piston reaches a critical velocity, PMMA crazing can emerge at the location where the major reflected wave and release wave meet. We show that the activation of PMMA crazing significantly enhances the energy dissipation ratio of the nanocomposite films, defined as the ratio between the dissipated energy through irreversible deformation and the input energy. The ratio maximizes at the critical Up when the PMMA crazing emerges and then decreases as Up further increases. We also find that a critical PMMA-graphene interfacial strength is required to activate PMMA crazing instead of interfacial separation. Additionally, layer thickness affects the amounts of input energy and dissipated energy for nanocomposite films under impact. This study provides important insights into the detailed dynamic deformation mechanisms and how nanointerfaces/nanostructures affect the energy dissipation capability of layered nanocomposite films.

Study on Dynamic Impact Response and Optimal Constitutive Model of Al-Mg-Si Aluminum Alloy.

Al-Mg-Si series aluminum alloy is a heat-treatment-strengthened alloy. Research on the impact resistance of Al-Mg-Si series aluminum alloy is of great significance to expand its application in engineering. Taking 6082-T6 aluminum alloy as the concrete research object, using the split Hopkinson pressure bar (SHPB) device, the dynamic mechanical response of the material under different temperatures and average strain rates was studied, and the service performance of the material under extreme conditions was determined. The absolute temperature rise was introduced to optimize the existing constitutive model. The results show that when the environment temperature is 298.15~473.15 K under high-speed impact, the internal thermal softening effect of the material is dominant in the competition with the work hardening, resulting in a decrease in the flow stress of the material. Through the analysis of the real stress-strain curve, it was found that the elastic modulus of the material was negatively correlated with the strain rate, negatively correlated with the temperature, and showed an obvious temperature-softening effect. Yield strength was negatively correlated with temperature and positively correlated with strain rate, which showed an obvious strain rate hardening effect. Based on SEM microscopic analysis, it was found that under given conditions, adiabatic shear bands appeared in some samples, and their internal structures demonstrated obvious change. It was judged that when high-speed impact occurs, cracks are induced at the shear bands, and the cracks will continue to develop along the adiabatic shear bands, resulting in many oblique cracks which will gradually become larger and eventually lead to material failure. Finally, based on the model, the strain rate and temperature softening terms were improved, and a rise in adiabatic temperature rise was introduced. The improved model can better describe the strain rate effect of the material and accurately describe its flow stress. It provides a theoretical basis for the engineering application of materials.

Durability Assessment Method of Hollow Thin-Walled Bridge Piers under Rockfall Impact Based on Damage Response Surface

Continuous rigid-frame bridges across valleys are often at risk of rockfalls caused by heavy rainfalls, earthquakes, and debris flow in a mountainous environment. Hollow thin-walled bridge piers (HTWBP) in valleys are exposed to the threat of impact from accidental rockfalls. In the current research, ANSYS/LS-DYNA is used to establish a high-precision rockfall-HTWBP model. The rockfall-HTWBP model is verified against a scaled impact test performed in previously published research. A mesh independence test is also performed to obtain an appropriate mesh size. Based on the rockfall-HTWBP model, the impact force, damage, and dynamic response characteristics of HTWBP under a rockfall impact are studied. In addition, a damage assessment criterion is proposed, based on the response surface model, combined with the central composite design method and Box–Behnken design method. The main conclusions are as follows: (1) the impact force of the rockfall has a substantial impulse characteristic, and the duration of the impulse load is approximately 0.01 s. (2) The impacted surface of the pier is dominated by the final elliptic damage, with conical and strip damage areas as the symmetry axis. The cross-sectional damage mode is from compression failure in the impact area and shear failure at the corner. (3) The maximum displacement occurs in the middle height of the pier. The maximum displacement increases with impact height, impact velocity, and rockfall diameter and decreases with the uniaxial compressive strength of the concrete. (4) The initial impact velocity and diameter of the rockfall are the most significant parameters affecting the damage indices. In addition, a damage assessment method, with a damage zoning diagram based on the response surface method, is established for the fast assessment of the damage level of impacted HTWBP.

Impact response prediction and optimization of SC walls using machine learning algorithms

The dynamic impact response of steel-plate composite (SC) walls is a vital index to assess their safety. By optimizing the design parameters within the requirements of relevant specifications, the impact-induced deformation can be reduced to ensure the protection of personnel and equipment inside the structures. To process the complicated nonlinear relationship between the wall deformation and design parameters rapidly and accurately, prediction models were constructed through such machine learning algorithms as support vector regression (SVR), artificial neural network (ANN), and gaussian process regression (GPR) in this study. Then these models were further validated by the existing test results. It shows that the root mean square error (RMSE), R-Squared (R2), and the time to complete one calculation of the GPR model are 2.74, 0.9591, and 0.58 ms respectively, which has obvious advantages in terms of accuracy, stability, and efficiency among the three machine learning models. Based on the well-trained GPR model, the design of a certain SC wall in an AP1000 nuclear power plant was optimized via the genetic algorithm, with the maximum deformation and the cost of SC walls as the optimization targets. The case study shows that the optimal solution set can reduce the maximum deformation by 10.1 % while keeping the total cost constant, or reduce the total cost by 18.8 % while keeping the maximum deformation constant.