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Copyright of Chinese Journal of Applied Mechanics is the property of Chinese Journal of Applied Mechanics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, interconnected porous Mg-2Zn-xY alloys with different phase compositions were prepared by various Y additions (x = 0.4, 3, and 6 wt. %) to adjust the compressive properties and energy absorption characteristics. Several characterization methods were then applied to identify the microstructure of the porous Mg-Zn-Y and describe the details of the second phase. Compressive tests were performed at room temperature (RT), 200°C, and 300°C to study the impact of the Y addition and testing temperature on the compressive properties of the porous Mg-Zn-Y. The experimental results showed that a high Y content promotes a microstructure refinement and increases the volume fraction of the second phase. When the Y content increases, different Mg-Zn-Y ternary phases appear: I-phase (Mg3Zn6Y), W-phase (Mg3Zn3Y2), and LPSO phase (Mg12ZnY). When the Y content ranges between 0.4% and 6%, the compressive strength increases from 6.30 MPa to 9.23 MPa, and the energy absorption capacity increases from 7.33 MJ/m3 to 10.97 MJ/m3 at RT, which is mainly attributed to the phase composition and volume fraction of the second phase. However, the average energy absorption efficiency is independent of the Y content. In addition, the compressive deformation behaviors of the porous Mg-Zn-Y are altered by the testing temperature. The compressive strength and energy absorption capacity of the porous Mg-Zn-Y decrease due to the softening effect of the high temperature on the struts. The deformation behaviors at different temperatures are finally observed to reflect the failure mechanisms of the struts.

• The chemical components of porous Mg were adjusted to design compressive properties. • The porous Mg-Zn-Y with different phase compositions were prepared by various Y content. • The effects of Y addition and test temperature on the compressive properties of the foams were studied. • A high Y content promotes the formation of the long-period stacking ordered phase. • The deformation behaviors at various temperatures were observed at macro and micro levels. In this study, interconnected porous Mg-2Zn- x Y alloys with different phase compositions were prepared by various Y additions (x = 0.4, 3, and 6 wt. %) to adjust the compressive properties and energy absorption characteristics. Several characterization methods were then applied to identify the microstructure of the porous Mg-Zn-Y and describe the details of the second phase. Compressive tests were performed at room temperature (RT), 200°C, and 300°C to study the impact of the Y addition and testing temperature on the compressive properties of the porous Mg-Zn-Y. The experimental results showed that a high Y content promotes a microstructure refinement and increases the volume fraction of the second phase. When the Y content increases, different Mg-Zn-Y ternary phases appear: I-phase (Mg 3 Zn 6 Y), W-phase (Mg 3 Zn 3 Y 2), and LPSO phase (Mg 12 ZnY). When the Y content ranges between 0.4% and 6%, the compressive strength increases from 6.30 MPa to 9.23 MPa, and the energy absorption capacity increases from 7.33 MJ/m3 to 10.97 MJ/m3 at RT, which is mainly attributed to the phase composition and volume fraction of the second phase. However, the average energy absorption efficiency is independent of the Y content. In addition, the compressive deformation behaviors of the porous Mg-Zn-Y are altered by the testing temperature. The compressive strength and energy absorption capacity of the porous Mg-Zn-Y decrease due to the softening effect of the high temperature on the struts. The deformation behaviors at different temperatures are finally observed to reflect the failure mechanisms of the struts. [ABSTRACT FROM AUTHOR]

Three-dimensional（3D） braided composite tubes, including 3D multi-layer braided, 3D fivedirectional surface-core braided, and 3D seven-directional braided tubes, were fabricated by vacuum assisted resin transfer molding. The yarn traces of the 3D braided composite tubes were systematically analyzed. The quasi‑static axial compression tests were carried out to investigate the effects of different braiding processes on the compression bearing capacity, failure mode and energy absorption performance of three‑dimensional braided composite tubes. The results showed that the axial bearing capacity and failure mechanism of circular tubes with different braided structures were significantly different. 3D multi‑layer braided tubes maintained a high volume content of circumferential yarn, which can effectively bear the axial load, making its axial bearing capacity significantly higher than the other two types of braided circular tubes. However, due to the weak load transfer performance between fibers, brittle failure was easy to occur, resulting in the worst energy absorption effect. 3D five‑directional surface‑core braided and 3D seven‑directional braided tubes had closely interwoven yarn structures，and the radial braided yarn can effectively limit the shear crack growth, thus leading to gradual and stable flowering failure. Such failure had better energy absorption characteristics. The fiber of the 3D five‑directional surface‑core braided tube broke more fully, and the energy absorption effect was the most excellent. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of High Pressure Physics is the property of Chinese Journal of High Pressure Physics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

CoCrMo sheet triply periodic minimal surface (sheet-TPMS) lattices with two different topologies (Neovius, IWP) were fabricated by laser power bed fusion (LPBF). Compressive behavior and energy absorption characteristic for each topology and direction were investigated. The unique pore channel structures of the fabricated Neovius and IWP lattices were well formed. The microstructural observation revealed that fine cellular substructures existed inside the sheets, and most of their constituent phases were confirmed to be the FCC phase. The results of the compression tests demonstrated that Neovius lattice had higher yield strength and first peak strength than IWP lattice, regardless of the compressive direction. As for the stress–strain curves of the lattices, an abrupt stress drop was found in neither of the two topologies. A comparison of the energy absorption characteristics confirmed that Neovius lattice had higher energy absorption efficiency and ideality than IWP lattice. The deformed structures showed that Neovius lattice displayed a gradual collapse mode, whereas a layer-by-layer compaction mode was indicated in IWP lattice. After the deformation, Neovius showed an evenly distributed and high fraction of the HCP phase caused by strain-induced martensitic transformation. The topology of lattice and strain-induced martensitic transformation effects on the compressive mechanical responses of the LPBF-built TPMS lattices were also discussed.

Combined simulation and test to investigate the collapse failure mode and energy absorption characteristics of wingding carbon fiber reinforced composite（CFRP[± 45°/90°]）/Al hybrid thin-walled circular tube under quasi-static axial compression load. Failure mode,Load-displacement curves and energy absorption characteristics were obtained under quasi-static axial crushing tests. A finite element model of hybrid tube was established according to samples. The simulation results with good agreement with the test were obtained by ABAQUS/Explicit,and the crushing failure behavior of the hybrid tube under quasistatic load was reproduced. Based on the simulation results,it was found that the initial crushing load,average crushing load,specific energy absorption and load efficiency of the mixing tube were increased by 97. 6%,93. 3%,57. 8% and 5. 9%,respectively. compared with the aluminum tube. The staged peaks and valleys of the crushing load were selected to analyze the shape of hybrid tube and the failure state of the fiber damage. The results show that when the hybrid tube is complete the fiber plays the main bearing role. In the crushing failure stage,the fiber damage failure mode changes with fiber winding angle,the crushing morphology of aluminum tube and the bonding interface state of CFRP/Al. Subsequently,the energy absorption characteristics of CFRP/Al hybrid circular tubes with three different structure forms were compared. It was found that hybrid circular tube with CFRP[90°/± 45°] wrapped the outside of the aluminum has the best energy absorption.

An experimental and numerical investigation has been carried out to compare the ballistic performance and energy absorption characteristics of plate and hemispherical shells made of 1100-H12 aluminium against projectile impact. For direct comparison, the thickness (1 mm) and diameter (68, 100, 150 and 200 mm) of both the target were kept identical. With varying incidence velocity within the range of sub-ordnance velocity, two distinct shapes of nosed projectiles, ogive and blunt, were impacted normally at the centre and crown of the plates and shells, respectively.A pressure gun was employed to perform the ballistic test whereas the numerical simulations were carried out through commercial finite element code ABAQUS and a close correlation between the experimental and numerical findings was observed. The response of both the targets was investigated in terms of failure mechanics, global and local deformation, ballistic limit, residual velocity and energy absorption in plastic deformation against both the projectiles. [ABSTRACT FROM AUTHOR]

Copyright of Engineering Mechanics / Gongcheng Lixue is the property of Engineering Mechanics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The effects of relative density of magnesium alloy foams on their dynamic mechanical properties and energy absorption characteristics are investigated. Split Hopkinson pressure bar (SHPB) is used to evaluate the dynamic compressive behaviors of magnesium alloy foams with different densities. The experimental results show that, with the increase in relative density, the yield stress and platform stress increase significantly while the densification strain decreases. Based on the experimental results, the fitting equations of yield stress and relative density are obtained. The energy absorption properties of metal foams are characterized by energy absorption per unit volume, energy absorption efficiency and ideal energy absorption efficiency. The higher the relative density of magnesium alloy foams is within a certain range, the higher the energy absorption capacity per unit volume is. The energy absorption efficiency decreases slightly, but it is steady at about 0.3, while the stress corresponding to the highest absorption efficiency increases. Magnesium foam is a kind of material with better protective performance, with the ideal energy absorbing efficiency reaching 0. 9. [ABSTRACT FROM AUTHOR]

Abstract: In this study, Zn–Al matrix composite foams reinforced with Al2O3 short fibers (Al2O3f/Zn–Al composite foams) were fabricated with the melt foaming process. The compressive properties and the energy absorption characteristics of the composite foams were investigated. To obtain the failure behaviour, the deformation of the composite foams was observed by scanning electron microscope (SEM). The results show that the microstructures of the foams have a significant effect on the compressive behavior of the composite foams. The strengthen mechanisms of the fiber on compressive properties of the composite foams were presented. Furthermore, the composite foams exhibit a high energy absorption characteristic. [Copyright &y& Elsevier]