Thin-Walled Structures最新文献

{"title":"Dynamic compressive behavior of functionally graded triply periodic minimal surface meta-structures","authors":"Xiaofei Ma,&nbsp;Ce Guo","doi":"10.1016/j.tws.2024.112544","DOIUrl":"10.1016/j.tws.2024.112544","url":null,"abstract":"<div><div>Triply periodic minimal surface (TPMS) lattice structures have gained considerable attention because of their light weight, high strength, and excellent energy absorption capabilities. However, the effect of the amplitude that can control the topological morphology of a TPMS on the dynamic properties of the TPMS structure is not yet fully understood, as previous studies have focused on the relative density and size as well as their quasi-static mechanical properties. In this study, three types of uniform sheet-based TPMS structures with different amplitudes and three types of functionally graded sheet-based TPMS structures were proposed. Experiments and numerical simulations were conducted under quasi-static and dynamic loading conditions. Six types of TPMS lattice structures made of 316 L stainless steel were manufactured via powder bed fusion. Quasi-static compression tests were performed at a strain rate of 0.001 s⁻¹. The experimental results indicate that increasing the amplitude can increase the elastic modulus, plateau stress, and energy absorption capacity of a structure. Moreover, the functional gradient amplitude structure has a higher energy absorption capacity, and the structures with line and log gradient strategies improved by 17.38 % and 35.43 %, respectively, compared to the uniform structure with an amplitude of 1. Additionally, an idealized rigid-linear plastic hardening (R-LPH) model was proposed to predict the mechanical response of the structures. The finite element method (FEM) was used to construct dynamic compression numerical models, and their validity was verified through split Hopkinson pressure bar (SHPB) tests at a strain rate of 695 s⁻¹. The mechanical response, deformation modes, and stress enhancement effects of the structures under dynamic compression were systematically studied. The results show that the mechanical performance and energy absorption capacity of the structures under dynamic impact loading increase with increasing strain rate. The critical velocity for the transition from the quasi-static mode to the impact mode increases with amplitude. For strain rates below 6000 s⁻¹, the strain rate effect is the main factor influencing the dynamic stress enhancement. As the strain rate continues to increase, the dynamic stress enhancement results from the combined effects of inertia and strain rate, with inertia effects gradually becoming the dominant factor. This study shows that functional gradient TPMS meta-structures have excellent mechanical and energy absorbing properties under quasi-static compression and dynamic compression, with potential applications in passive safety protection.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of energy absorption characteristics of novel lattice structures inspired by Helleborus petticoat flower and fish scale pattern for different loading orientations","authors":"Brijesh H. Patel,&nbsp;Pulak Mohan Pandey","doi":"10.1016/j.tws.2024.112542","DOIUrl":"10.1016/j.tws.2024.112542","url":null,"abstract":"<div><div>In the present work, arc-shaped, thin-strut-based structures were developed by taking inspiration from the cup shaped Helleborus petticoat flower and fish scale pattern. The designed structures have been additively manufactured with a fused deposition modeling process. In this work, one fish scale pattern inspired structure was developed and named FS structure, whereas two flower-inspired structures were developed and named FL4 and FL8 structures. The static compression tests were conducted to study stress-strain behavior of the proposed structures in two different orientations, viz. orientation:1 (along z-axis) and orientation:2 (along x-axis). Furthermore, the mechanical responses and energy absorption characteristics are comprehensively examined for the proposed structures in both orientations. The structures exhibited higher specific energy absorption (SEA) in orientation:1 compared to orientation:2. The increment in SEA is ∼29 % for FS, ∼298% for FL4, and ∼115% for FL8 structures in orientation:1 compared to orientation:2. Meanwhile, the proposed bio-inspired structures are capable of absorbing energies in the range of 0.06-0.47 MJ/m³, up to densification. Finally, SEA of proposed structures is compared with the SEA of other structures in the available literature.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142425680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Axial hysterestic behavior of prestressed CFDST columns for lattice-type wind turbine towers","authors":"Kai-Yuan Jin ,&nbsp;Xu-Hong Zhou ,&nbsp;Chao Hu ,&nbsp;Yu-Hang Wang ,&nbsp;Yong-Sen Lan ,&nbsp;Yang Zhou","doi":"10.1016/j.tws.2024.112565","DOIUrl":"10.1016/j.tws.2024.112565","url":null,"abstract":"<div><div>The escalating power outputs of wind turbines necessitate enhanced load-bearing capabilities in their support structures. A new type of prestressed concrete-filled double skin steel tubular (CFDST) lattice-type wind turbine tower has been proposed to replace the original steel-concrete hybrid tower. The corner columns of the tower are made of prestressed CFDST columns, with the prestressing steel strands situated within the hollow area. While numerous studies have researched the axial characteristics of concrete-filled steel tubular (CFST) columns, investigations into prestressed CFDST columns subjected to axial cyclic loading remain sparse. To address this research gap, this study carried out the experimental and finite element studies of eight prestressed CFDST columns under axial tensile, axial compressive, and tensile-compressive cyclic loads. Detailed analyses of failure modes, hysteresis curves, stiffness degradation, skeleton curves and ductility were conducted. The test results indicate that the prestressing enables the concrete to establish good contact with the steel tubes, thereby preventing the premature cracking. At a cost of approximately 6.8 % reduction in axial compressive load, the axial tensile load of the structure is enhanced by about 47.2 %. Furthermore, an advanced finite element (FE) model, refined based on the test, closely matched the experimental data, thereby validating its accuracy for subsequent mechanism and parameter investigation.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Energy absorption characteristics of bio-inspired multi-corner CFRP tubes under axial quasi-static and dynamic loading","authors":"Jie Fu ,&nbsp;Qiang Liu ,&nbsp;Xiaokang Ma ,&nbsp;Ming Cai","doi":"10.1016/j.tws.2024.112551","DOIUrl":"10.1016/j.tws.2024.112551","url":null,"abstract":"<div><div>The multi-corner design approach can effectively enhance the energy absorption capacity of thin-walled metallic tubes under axial quasi-static and dynamic loading conditions. However, its efficacy in augmenting the crashworthiness performance of carbon fiber reinforced plastic (CFRP) tubes remains inconclusive, particularly due to the different failure mechanisms and pronounced strain rate effects inherent to CFRP materials compared to their metallic counterparts. Therefore, a type of bio-inspired multi-corner CFRP tube structure was designed by mimicking the non-convex cross-sectional shape of the root of ceiba pentandra tree, and its axial crushing responses were studied experimentally and numerically. Quasi-static compression and dynamic impact tests were conducted to compare the energy absorption capabilities of square and bio-inspired tubes with the same mass. The results showed that the specific energy absorption (<span><math><mrow><mi>S</mi><mi>E</mi><mi>A</mi></mrow></math></span>) of the square CFRP tube increased after adopting the bio-inspired design; however, different percentages of increase in <span><math><mrow><mi>S</mi><mi>E</mi><mi>A</mi></mrow></math></span> values were found under quasi-static and dynamic crush conditions, 13.5 % and 4 %, respectively. With the aid of finite element analysis and electron scanning technologies, the energy absorption mechanisms of bio-inspired tubes were further studied. It was found that the increase in <span><math><mrow><mi>S</mi><mi>E</mi><mi>A</mi></mrow></math></span> values was attributable to the increased number of axial splitting and secondary squeezing effects between internal fronds in the crushed tubes. Moreover, most of the fibers at the corner in a tube failed in tensile fracture mode during quasi-static testing, whereas they failed in both tensile and shearing fracture mode in dynamic testing, thereby leading to a reduction of energy absorption.</div><div>Finally, two novel multi-corner tubes based on bio-inspired design and corner fractal design methods were proposed and they showed higher SEA values than initial one under dynamic impact.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142425678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In-plane crushing behavior and energy absorption of CFRP honeycombs with different core topologies","authors":"Levent Pehlivan ,&nbsp;Cengiz Baykasoğlu","doi":"10.1016/j.tws.2024.112566","DOIUrl":"10.1016/j.tws.2024.112566","url":null,"abstract":"<div><div>The in-plane crushing behavior and energy absorption performance of carbon fiber reinforced polymer (CFRP) honeycombs with different core topologies were experimentally investigated under uniaxial loading conditions. Three types of CFRP honeycomb core topologies (i.e. circular, square and hexagonal) with different cell wall thicknesses and heights were considered in the designs. The honeycomb samples were fabricated by the molding and bonding process, which is widely used in the easy, fast and economical manufacturing of thin-walled honeycomb structures. A total of twenty-seven sample groups were experimentally tested for each loading condition, in which honeycomb samples with different core topologies were designed to have almost the same weights for a meaningful comparison. The experimental results revealed that all honeycomb designs have higher in-plane compression strength in the expansion direction, and hexagonal honeycombs showed the highest strength and energy absorption performance in both directions due to their stable load-carrying capacity and outstanding force efficiency. In particular, the experimental findings showed that the crushing strength and the specific energy absorption of CFRP honeycomb structures can be improved up to 6.1 and 4.2 times, respectively, by properly adjusting the cell wall thickness and height parameters. The results also revealed that the proposed lightweight CFRP honeycombs with the structural densities of 155–283 kg/m³ showed better in-plane crushing performance than many competing cellular topologies.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact responses of steel–concrete–steel–gradient aluminum foam energy absorbing panels: Experimental and numerical studies","authors":"Junyi Chen ,&nbsp;Yonghui Wang ,&nbsp;Hongyuan Zhou ,&nbsp;Huanan Xu","doi":"10.1016/j.tws.2024.112552","DOIUrl":"10.1016/j.tws.2024.112552","url":null,"abstract":"<div><div>A novel steel–concrete–steel–gradient aluminum foam energy absorbing panel (SCSGF-EAP) has been proposed for improving the impact resistance of existing structures. The impact resistant performances of the SCSGF-EAP were evaluated through the drop weight impact tests and numerical simulations. The varying thickness of gradient aluminum foam and concrete core was considered in the drop weight impact tests. All the specimens presented a consistent failure mode, which included local indentation and global flexure of SCS panel and crushing of gradient aluminum foam. The Finite Element (FE) model was developed through adopting LS-DYNA for studying the impact resistance of SCSGF-EAP, and the comparisons exhibited that numerical results agreed well with experimental data. The internal energy of different components of specimen was determined by numerical model, and the gradient aluminum foam absorbed the majority of the impact energy. Finally, parametric studies were adopted to determine influences of the initial momentum and kinetic energy of impactor, as well as the density of gradient aluminum foam and impact location on the impact response of SCSGF-EAP.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142426293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing the electromagnetic shielding and mechanical properties of CF/PEEK composites via low-concentration fluff and Ni-Co alloy plating","authors":"Shu Zhu ,&nbsp;Song Yan ,&nbsp;Yu Gao ,&nbsp;Mingcheng Qu ,&nbsp;Yue Li ,&nbsp;Jianfeng Zhou ,&nbsp;Yan Dong ,&nbsp;Weizhao Zhang","doi":"10.1016/j.tws.2024.112563","DOIUrl":"10.1016/j.tws.2024.112563","url":null,"abstract":"<div><div>Carbon Fiber Reinforced Composites (CFRC) are increasingly used in aircraft to minimize weight and maximize structural designability. However, CFRCs have limitations in electrical conductivity and Electromagnetic Interference (EMI) resistance. This study introduces a process to overcome these drawbacks by chemically plating Carbon Fiber (CF) fabrics with a thin layer of Nickel-Cobalt (Ni-Co) alloy, thereby improving electrical conductivity. Subsequently, Sulfonated Polyether Ether Ketone (SPEEK) was applied to the Nickel-Cobalt coated Carbon Fibers (NiCo@CF). The resulting fuzzy surface effectively enhanced the interfacial interactions within the PEEK matrix. The results showed that the tensile strength, tensile modulus, flexural strength, and flexural modulus of the composite panels treated with 0.1 wt.% SPEEK sizing significantly increased by 32.3 %, 26.0 %, 167.9 %, and 20.7 %, respectively, compared to NiCO@CF/PEEK composite panels treated with no SPEEK sizing agent. Additionally, the introduction of SPEEK fostered a shift in the primary fracture mechanism from fiber pull-out or debonding to fiber fracture. Remarkably, compared to CF/PEEK composites, the electromagnetic shielding efficiency of NiCo@CF/PEEK was increased by 88.98 %, reaching 46.15 dB. Long-term testing of the S-NiCO@CF/PEEK composites in a humid and hot environment confirmed consistent electromagnetic and mechanical properties, alongside good fatigue and aging resistance. These advances make the S-NiCO@CF/PEEK composites promising for broader applications in the aircraft and aerospace fields.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and numerical research on deformation of square plates with circular holes under blast load","authors":"Qingyuan Wei ,&nbsp;Dongyan Shi ,&nbsp;Ziqi Wu ,&nbsp;Yanpei Zhou ,&nbsp;Xiongwei Cui","doi":"10.1016/j.tws.2024.112543","DOIUrl":"10.1016/j.tws.2024.112543","url":null,"abstract":"<div><div>The response and failure of plates under blast loads are critical concerns in engineering. Plates with preformed holes may exhibit significantly different behaviors compared to those without holes, and detailed research on this topic remains limited. In this study, the deformation of square plates with circular holes subjected to blast loads was investigated through experiment and simulation methods. Square plates with circular holes were designed with three hole positions and two hole diameters. Far-field explosion experiments measured the displacement fields of the plates and the overpressure on the plate frame. Subsequently, LS-Dyna simulation models were established using a two-dimensional model to three-dimensional model mapping, with numerical results aligning with experimental results. Additional numerical calculations with larger charge mass supplemented the experimental cases, analyzing the influence of holes on plate response. It was found that the presence of a hole influenced the displacement field, with notable local effects such as significantly increased displacement near the hole. The presence of a hole can shift the position of maximum equivalent plastic strain from the plate edge to the hole edge. The influence of the size and position of a hole on the deformation and equivalent plastic strain were discussed.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on the PDDO-based meshfree method in numerical simulation of shell ductile fracture considering a non-local GTN model","authors":"Liu Fan ,&nbsp;Shi Yang ,&nbsp;Hu Yu-meng ,&nbsp;Feng Guo-qing","doi":"10.1016/j.tws.2024.112521","DOIUrl":"10.1016/j.tws.2024.112521","url":null,"abstract":"<div><div>A meshfree method is developed based on the peridynamic differential operator (PDDO) for ductile damage and fracture problems in metal shell structures. The kinematic equations coupled to classical continuum mechanics (CCM) are derived with the motion variables discretized by the PDDO. The elastoplastic and fracture behavior of the material are described by applying the Gurson-Tvergaard-Needleman (GTN) model with shear modification, and the non-local form of the model improves the computational convergence for different modeling scales. The zero-energy model in numerical computations is effectively controlled by introducing an hourglass force based on the average displacement state. The particles contact algorithm and multi-crack visualization algorithm are developed to simulate the fracture of shell structures under collision loads. By comparing with experiments, it is verified that the proposed PDDO-based meshfree method can accurately predict the ductile fracture of shell structures subjected to in-plane and out-of-plane loads.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chaotic self-beating of left ventricle modeled by liquid crystal elastomer","authors":"Xin Sun,&nbsp;Kuan Zhou,&nbsp;Peibao Xu","doi":"10.1016/j.tws.2024.112540","DOIUrl":"10.1016/j.tws.2024.112540","url":null,"abstract":"<div><div>Self-vibration systems using active materials generate sustained vibrations spontaneously through synergistic actions between internal structure and external environment. Therefore, the self-vibration systems have a wide application prospect in bionic design and soft robots. Inspired by the human left ventricle, a novel chaotic self-beating system modeled by an electrothermal responsive liquid crystal elastomer balloon is proposed. To study the self-beating characteristics of the liquid crystal elastomer left ventricle, a simplified theoretical framework is formed by combining the electric joule heat conduction model, the left ventricle circulatory system model and the dynamic principle. The numerical results show that the left ventricle has two typical self-beating modes: periodic beating and chaotic beating. The mechanisms of periodic beating and chaotic beating are elucidated by analyzing the balance between the work done by each force on the left ventricle. In addition, the effects of key system parameters on self-beating behavior are investigated in detail. This research will promote the application of chaotic dynamics in artificial hearts and medical devices, while providing a new perspective for the study of chaotic behavior and mechanism in biology.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}