Abstract Based on the inverse piezoelectric effect and other characteristics of piezoelectric ceramics, a new type of piezoelectric variable friction damper is developed, and the output performance test of piezoelectric ceramic actuator and piezoelectric variable friction damper is carried out, and the parametric mechanical model of the damper is established by using Simulink to carry out numerical simulation, and compared and analyzed with the test results. The results of the study show that the simulation and the test present a good regular agreement. With the increment of loading voltage, the displacement deformation and zero-displacement thrust of piezoelectric ceramic actuator are approximately linear with the loading voltage; when the loading voltage is increased by 15V every time, the test value of the output damping force of the damper increases by 259.66N on average step by step, and the simulated value increases by 256.14N step by step, and the damping force has a linearly incremental relationship with the voltage and the slope of the linear increase is 16.434. ceramics developed agreement zerodisplacement zero V time 25966N N 259 66N 25614N 256 14N 16434 16 434 16.434 25 1643 1 43 16.43 2 164 4 16.4 16.

Abstract To further improve the strike accuracy and penetration power of explosively-formed projectile (EFP) after long-distance flight, a polygonal charge capable of forming EFP with tail fins was designed during the study. A model for calculating the EFP velocity was derived from the effective charge and detonation projection theories with the integration of calculus. The circumferential velocity distributions of EFP formed using polygonal charges were obtained using this model, and the mechanisms underlying the formation of tail fins were elucidated. The feasibility of using this polygonal charge to form tail fin EFP was verified by conducting multi-media soft recovery tests and numerical simulations. Furthermore, the feasibility of forming tail fin EFP using polygonal charges with different numbers of sides and the effects of the structural parameters of a hexagonal charge on the formation of tail fin EFP were investigated by simulation. The ranges of optimal values for the structural parameters of a hexagonal charge capable of forming high-performance tail fin EFPs were determined. explosivelyformed explosively (EFP longdistance long distance flight study calculus elucidated multimedia multi media simulations Furthermore simulation highperformance high performance determined

Abstract This work introduces a new family of strain tensors based on the hyperbolic sine function: The Generalized Hyperbolic Sine (GHS). This family is obtained by using any given strain measure as an argument in a normalized hyperbolic sine function. Particularly, this paper adopts the Seth-Hill family as an argument and shows how some drawbacks of the classical strain measures can be overcome by means of the proposed strain family. A broad analytical study of pure deformation modes (simple axial extension, equi-biaxial loading and simple shear) is presented to show the behavior of the proposed strain family and investigate the physical coherence of their responses. Obtained results are promising as the GHS family proved itself capable of enhancing the physical behavior of the Seth-Hill strain measures and providing versatility with the addition of just one material constant with clear physical meaning. Materials investigated in the article are isotropic and homogeneous. The proposed Hookean-type hyperelastic models can be applied for both incompressible and compressible materials without additional strain energy density function changes. GHS. . (GHS) Particularly SethHill Seth Hill extension equibiaxial equi biaxial shear responses meaning homogeneous Hookeantype Hookean type changes (GHS

Abstract The detonation of conventional munitions due to accidents or hostile actions causes urban destruction and loss of life, underscoring the need for improved safety measures. This study addresses the scarcity of research in munitions safety by investigating the threat of small and medium munitions. Experimental setups using 50mm shaped charges were developed and simulated with ANSYS AUTODYN, featuring JH-2 explosive and oxygen free high conductivity copper liner. Aluminum buffer plates were added to align jet energy levels with small and medium munitions' requirements. Safety assessments of JH-2 explosive against standard charges utilized φ45x40mm JH-2 targets covered with steel. Numerical simulations employed the Lee-Tarver ignition and growth model, comparing JH-2 explosive response with insensitive explosives like LX-17 and TATB. Results showed JH-2's failure in experimental tests, corroborated by simulations, while TATB and LX-17 remained stable. This study advocates for the adoption of cost-effective, insensitive explosives in next generation weaponry to mitigate unintentional detonations. life measures mm AUTODYN JH2 JH 2 JH- liner requirements φxmm φ x steel LeeTarver Lee Tarver model LX17 LX 17 LX-1 JH2s JHs s tests stable costeffective, costeffective cost effective, effective cost-effective detonations LX1 1 LX-

Abstract The study aims to enhance the bonding strength in reinforced concrete using a novel Auxetic Tubular Deformed Rebar (ATDR). A high-resolution non-linear finite element model was developed to perform numerical analysis of pull-out tests (PoT). Two sets of numerical simulations were conducted: one to replicate the concrete behavior under compression and tension tests, and the other for PoT, validated with experimental and numerical data. Numerical tests utilized a microplane model with plasticity–damage, regularized by an implicit gradient. Auxetic geometry involves adding ellipsoidal orifices to the rebar surface. Comparing the behavior of ATDR with the conventional rebar, we observed an increase in the negative value of Poisson's ratio, resulting in higher normal and shear forces, enhancing adherence. This study presents the first comprehensive simulation of Auxetic Metamaterial Rebar in concrete, offering a promising approach to enhance bond strength. Further research, both numerical and experimental, is essential to assess Auxetic Reinforcement's mechanical behavior in diverse structural elements and load scenarios. ATDR. . (ATDR) highresolution high resolution nonlinear non linear pullout pull out PoT. PoT (PoT) conducted data plasticitydamage plasticity damage plasticity–damage gradient surface Poissons Poisson s ratio forces adherence research Reinforcements Reinforcement scenarios (ATDR (PoT

Abstract In this paper, the penetration resistance of 6061 aluminum plates to explosively formed projectiles (EFPs) at the incidence angles of 0°, 15°, 30°, and 45° was studied. The penetration process was roughly divided into three typical stages—the plastic flanging stage of the target, the righting stage of the projectile, and the plug formation stage of the target. Through the energy analysis, the energy consumption of the aluminum plate increased with the increase in the incidence angle during the entire penetration process. Through the microscopic analysis of the perforated wall surface of the aluminum plate, it was found that there were distinct boundaries and differences between the plastic reaming zone and the punching plug fracture zone.. Overall, four kinds of classification modes were proposed for the damage of the aftereffect plate, which provides a method to evaluate the aftereffect of EFP oblique penetration into 6061 aluminum plates. paper 606 EFPs (EFPs 0 0° 15 15° 30 30° 45 studied stagesthe stages target projectile zone. Overall 60 1 3 4 6

Abstract To study the propagation and evolution of one-dimensional elastoplastic waves within the system under rectangular, trapezoidal, and half-sine incident waves, leveraging elastoplastic incremental wave theory and numerical simulation calculations, the research qualitatively investigates the distribution and evolution of the stress field within the specimen, the impact of Bar 2 parameters, and the deformation characteristics of Bar 2 under these three types of incident waves. The findings indicate: Regardingthe overall stress uniformity of Bar 2 during the entire loading phase, the rectangular incident wave is the most effective, while the half-sine and trapezoidal waves are more advantageous for analyzing the stress conditions in Bar 2 during the early loading phase. The diameter and dimensionless density of the specimen significantly influence the stress non-uniformity, showing an approximate negative and positive correlation, respectively. onedimensional one dimensional halfsine half sine calculations parameters indicate phase effective nonuniformity, nonuniformity non uniformity, non-uniformity correlation respectively

Abstract This paper introduces the Julia programming language as a dynamic, cost-effective, and efficient framework for implementing structural analysis packages. To achieve this, the finite element method was implemented for plane frames addressing the elastic instability problem through the Finite Element Method (FEM). Julia is a language open source, multiplatform, high-level and high-performance for technical and scientific computing, its compiler allows you to achieve speeds comparable to languages such as C and FORTRAN, but with more productive development dynamics due to its programming flexibility. Benchmarks between Julia and MATLAB are employed to discuss the processing costs, the programming techniques and paradigms used for computational performance. The results demonstrate that Julia performed the same analysis as the language used for comparison in 88.40% of the time, in addition to the fact that in loops comparisons case it reached 41.7% of the time for iteration, confirming its significant potential as a development tool of computational packages for structural analysis and scientific computing in general. dynamic costeffective, costeffective cost effective, effective cost-effective this FEM. FEM . (FEM) source multiplatform highlevel high level highperformance performance FORTRAN flexibility costs 8840 88 40 88.40 417 41 7 41.7 iteration general (FEM 884 8 4 88.4 41. 88.

Abstract The use of simple bar elements in nonlinear structural finite element formulations has the academic advantage of uncoupling element technology issues from the structural phenomena to be observed. In this work, we present a finite element setting for the formulation of different nonlinear material models applied to the transient analysis of trusses. While nonlinear elasticity is considered by studying a Hooke-like linear relationship between different pairs of nonlinear measures of stress and strain, hyperelasticity is formulated using Ogden’s model. Viscoelasticity is introduced using a generalized Kelvin rheological model to account for strain rate effects. The finite kinematics is set in a corotational total Lagrangian description where the virtual work is described using the Second Piola-Kirchhoff and the Green Lagrange measures. Although the derivation is omitted, the consistent tangent moduli are given for all these cases. Numerical problems involving simultaneously different truss models are studied and made available as benchmarks since little comparative data is found in literature. observed trusses Hookelike Hooke like Ogdens Ogden s effects PiolaKirchhoff Piola Kirchhoff omitted cases literature

Abstract Slender reed straws in nature can withstand heavy weight of reed spikes and lateral wind force, and thus show good mechanical properties, especially compression resistance and shear resistance. In the paper, the quasi-static and dynamic mechanical properties of reed straws were studied. Three influencing factors of the straws were set according to the nodes (node-containing, node-free), location section (location 1, 2, 3, 4, 5), and moisture content (low, medium, high). The tensile strength of node-free reed straws with low moisture content ranged from 55.40 to 68.14 MPa at different locations. The axial compressive strength of node-containing straws was higher than that of node-free straws, and the influence of moisture content on the axial compressive strength was more obvious. The radial compressive strength of node-containing straws is 13.00 times higher than that of node-free straws in the corresponding part. The bending strength of straws gradually increases from the top to the root, and it is further enhanced with higher moisture content. The axial impact peak load of node-containing straws is up to 1.27 times that of node-free straws, and the axial impact peak load of straws with high moisture content is 1.40 times higher than that of straws with low moisture content in the corresponding part. The radial impact strength of reed straws gradually increases from the top to the root. In terms of bending impact strength, the impact toughness of reed straws ranges from 0.030 to 0.14 J·cm2, and the specific energy absorption ranges from 1.09 to 4.35 J/kg. Because of the excellent mechanical properties, reed straws provide important material performance data for the engineering field and inspire the design of new engineering materials or structures by improving strength and reducing weight. force paper quasistatic quasi static studied nodecontaining, nodecontaining node containing, containing (node-containing nodefree, nodefree free , node-free) 1 2 3 4 5, 5 5) low, (low medium high. . high) 5540 55 40 55.4 6814 68 14 68.1 locations obvious 1300 13 00 13.0 part root 127 27 1.2 140 1.4 0030 0 030 0.03 014 0.1 Jcm2 Jcm J cm2 cm J·cm2 109 09 1.0 435 35 4.3 Jkg kg J/kg 554 55. 681 6 68. 130 13. 12 1. 003 03 0.0 01 0. J·cm 10 43 4.

Abstract As an ideal impact energy absorber, the external inversion process of thin-walled metal tubes over circular dies has been studied theoretically since 1960s. However, in the most existing theoretical models, the curvature in the deformation area is a constant and only the steady inversion force is studied. Limited research has been conducted on the whole inversion process. In this study, from experimental and numerical results, the curvature is found to be varying and the whole inversion process can be divided into two stages by three states. Then a modified geometric model is proposed and the force displacement curves is derived. Next, it has been observed that current theoretical results exhibit greater conformity with experimental and numerical results. Finally, the effects of the tube wall thickness, tube average radius and die radius on crashworthiness indicators are studied theoretically by the verified theoretical model. These outcomes offer valuable reference for further research on tube inversion forming and energy absorption characteristics of external inversion mode. absorber thinwalled thin walled 1960s s However models study states derived Next Finally thickness mode

Abstract For solving a large amount of data processing and reducing the cost to improve detection accuracy, this paper proposes an intelligent detection model for railway vehicle wheels flat. We propose an automatic data processing algorithm for labeling large-scale data to maximize the benefits of each experiment data. To improve the generalization of the detection model to improve the accuracy, we combine the vehicle dynamics simulation data and the simulation experiment data based on the single wheel rolling test bench to construct the data set for detecting the wheel flat. Different from the existing detection models, this paper provides a method for constructing the data sets, which is used to assist machine learning in constructing the intelligent detection model. The data set and its construction method can also promote the application of data mining in the field of railway transportation. This paper verified the effectiveness of the features obtained from data processing in the detection model. The data set is used to detect and identify the wheel flat and the recognition accuracy is 98.6%. largescale scale models sets transportation 986 98 6 98.6% 9 98.6 98.

Abstract This paper presents an investigation on the structural condition of a cable-stayed footbridge based on data collected in two dynamic tests, performed at different times. The natural frequencies and mode shapes were obtained by applying output only modal identification methods. At least four experimental mode shapes of the footbridge and stay cables were identified in Operational Modal Analysis. A 3D finite element model of the footbridge was calibrated by adjusting its dynamic properties to the experimentally identified in the first test. The procedure showed, besides an approximation of the dynamic behavior, an approximation of its static behavior, which was confronted to the structural design. The analysis found a discrepancy between the required reinforcement based on the updated model stresses and the existing steel reinforcement. The second test, performed one year later, provided different natural frequency values to those found in the first test and the spectrum presented inconsistency in one of its peaks. It was concluded that the structure presents conditioning problems, thus warning to future structural problems. cablestayed cable stayed tests times methods Analysis D showed behavior design later peaks problems

Abstract Based on the theory of solid porous media with pores, the dynamic response of layered saturated frozen soil under uniform moving load is studied. Firstly, the governing equation of saturated frozen soil is established. Then, the Fourier integral transform is used to decouple the governing equation of saturated frozen soil, and the general solution of the potential function is obtained, and the corresponding force and displacement of each layer of saturated frozen soil are derived. Finally, using the transfer matrix method, combined with the continuous condition, the semi-analytical solution of the layered saturated frozen soil medium in the frequency domain under the surface permeable condition is derived. After verifying the accuracy of the solution by comparing the model degradation with the existing literature, the effects of soil shear modulus, load moving speed, temperature, contact parameter and frequency on the dynamic response are analyzed in detail. The results show that the order of soft and hard soil layers is of great significance to accurately evaluate the dynamic response of saturated frozen soil. pores studied Firstly established Then obtained derived Finally method semianalytical semi analytical literature modulus speed temperature detail

Abstract A damage detection method based on the quadratic correlation function of strain responses (QCoS) and pattern matching degree (PMD) is proposed in the present study. For this method, only QCoS is calculated in time domain by strain responses, and there is no need for modal parameter extraction and analytical model of structures. It is proved that QCoS is the function of modal parameters of structures, such as natural frequency, mode shape and damping ratio. Numerical simulations of a simply supported steel beam are analyzed for illustrating the effect of excitation position, reference point and damage level on QCoS, respectively. The results show that QCoS is sensitive to local damage in the structure and robust to measurement noise. Therefore, QCoSs are used to construct the damage feature vector. The damage detection is performed by comparing the damage feature vectors before and after the structural damage. Three simply supported aluminum beams are tested in the laboratory to demonstrate the effectiveness and practicability of the proposed method. (QCoS PMD (PMD study structures frequency ratio position respectively noise Therefore vector