Thin-walled structures have been used in many fields due to their superior mechanical properties.In this paper,two types of hierarchical multi-cell tubes,inspired by the self-similarity of Pinus sylvestris,are propose...Thin-walled structures have been used in many fields due to their superior mechanical properties.In this paper,two types of hierarchical multi-cell tubes,inspired by the self-similarity of Pinus sylvestris,are proposed to enhance structural energy absorption performance.The finite element models of the hierarchical structures are established to validate the crashworthiness performance under axial dynamic load.The theoreticalmodel of themean crushing force is also derived based on the simplified super folded element theory.The finite element results demonstrate that the energy absorption characteristics and deformation mode of the bionic hierarchical thin-walled tubes are further improved with the increase of hierarchical sub-structures.It can be also obtained that the energy absorption performance of corner self-similar tubes is better than edge self-similar tubes.Furthermore,multiobjective optimization of the hierarchical tubes is constructed by employing the response surface method and genetic algorithm,and the corresponding Pareto front diagram is obtained.This research provides a new idea for the crashworthiness design of thin-walled structures.展开更多
This research introduced the design,analysis and optimization of bionic shrimp chela multi-cell tubes(BSCMTs)in bending by embedding an arthropod's microstructure inside a thin-walled square structure.A three-poin...This research introduced the design,analysis and optimization of bionic shrimp chela multi-cell tubes(BSCMTs)in bending by embedding an arthropod's microstructure inside a thin-walled square structure.A three-point impact bending finite element model was,in the first instance,correlated with physical tests and then modified to assess the energy absorption performance of bionic multi-cell tubes considering initial peak force,specific energy absorption and mean crushing force.Following a complex proportional assessment(COPRAS)approach and optimization phases,results demonstrated that the BSCMT with a W-shape section had the best energy absorption characteristics and should be considered in future as a possible contender for vehicle B-pillar structures that are subjected to bending and require excellent energy absorption properties to protect the occupants in high-speed impact collisions.展开更多
Gravity sampling is of vital importance for sampling seabed sediments and understanding submarine sedimentary environments and resources.In this study,a new bionic sampler tube(BST)with non-smooth surface for low-dist...Gravity sampling is of vital importance for sampling seabed sediments and understanding submarine sedimentary environments and resources.In this study,a new bionic sampler tube(BST)with non-smooth surface for low-disturbance and rapid sampling is presented.The BST with depressions and swellings on its surface was designed on the model of the non-smooth surface of the dung beetle.Sufficient theoretical calculations,numerical simulations,and experimental tests were carried out to study its sampling performance.The penetration depth,sample length,and frictional drag of the sampler tube were calculated.The finite element model and the coupled Eulerian-Lagrangian(CEL)method were used to analyze and compare its sampling performance.Laboratory and field gravity sampling tests were conducted and the results demonstrated the advantages of the BST in improving sampling performance and in reducing adhesion and drag.展开更多
为解决火力发电厂凝汽器压力不达标的问题,提出了凝汽器管束采用新型仿生布管形式,并用不锈钢管替代铜管的优化措施。系统投运测试表明:通过优化凝汽器管束布置方式,凝汽器压力降低了0.88 k Pa,过冷度小于0.5℃,凝汽器热力特性得到很大...为解决火力发电厂凝汽器压力不达标的问题,提出了凝汽器管束采用新型仿生布管形式,并用不锈钢管替代铜管的优化措施。系统投运测试表明:通过优化凝汽器管束布置方式,凝汽器压力降低了0.88 k Pa,过冷度小于0.5℃,凝汽器热力特性得到很大改善,主凝结区不存在涡流和空气积聚现象,机组可节约标准煤耗2.64 g/(k W·h),经济效益和环保效益显著。展开更多
基金The authors are grateful to the National Natural Science Foundation of China(Grant No.11902183)the Doctoral Research Foundation of Shandong University of Technology(Grant No.4041/418017).
文摘Thin-walled structures have been used in many fields due to their superior mechanical properties.In this paper,two types of hierarchical multi-cell tubes,inspired by the self-similarity of Pinus sylvestris,are proposed to enhance structural energy absorption performance.The finite element models of the hierarchical structures are established to validate the crashworthiness performance under axial dynamic load.The theoreticalmodel of themean crushing force is also derived based on the simplified super folded element theory.The finite element results demonstrate that the energy absorption characteristics and deformation mode of the bionic hierarchical thin-walled tubes are further improved with the increase of hierarchical sub-structures.It can be also obtained that the energy absorption performance of corner self-similar tubes is better than edge self-similar tubes.Furthermore,multiobjective optimization of the hierarchical tubes is constructed by employing the response surface method and genetic algorithm,and the corresponding Pareto front diagram is obtained.This research provides a new idea for the crashworthiness design of thin-walled structures.
基金supported by the 2022 Guangxi University Young and Middle-aged Teachers’Basic Research Ability Improvement Project(Grant No.2022KY0781)Scientific Research Funds of Guilin University of Aerospace Technology(Grant No.XJ21KT18)the Major Special Projects of Liuzhou Science and Technology Plan(Grant No.2022ABA0106).
文摘This research introduced the design,analysis and optimization of bionic shrimp chela multi-cell tubes(BSCMTs)in bending by embedding an arthropod's microstructure inside a thin-walled square structure.A three-point impact bending finite element model was,in the first instance,correlated with physical tests and then modified to assess the energy absorption performance of bionic multi-cell tubes considering initial peak force,specific energy absorption and mean crushing force.Following a complex proportional assessment(COPRAS)approach and optimization phases,results demonstrated that the BSCMT with a W-shape section had the best energy absorption characteristics and should be considered in future as a possible contender for vehicle B-pillar structures that are subjected to bending and require excellent energy absorption properties to protect the occupants in high-speed impact collisions.
基金the Finance Science and Technology Project of Hainan Province(No.ZDKJ202019)the National Natural Science Foundation of China(No.41976055).
文摘Gravity sampling is of vital importance for sampling seabed sediments and understanding submarine sedimentary environments and resources.In this study,a new bionic sampler tube(BST)with non-smooth surface for low-disturbance and rapid sampling is presented.The BST with depressions and swellings on its surface was designed on the model of the non-smooth surface of the dung beetle.Sufficient theoretical calculations,numerical simulations,and experimental tests were carried out to study its sampling performance.The penetration depth,sample length,and frictional drag of the sampler tube were calculated.The finite element model and the coupled Eulerian-Lagrangian(CEL)method were used to analyze and compare its sampling performance.Laboratory and field gravity sampling tests were conducted and the results demonstrated the advantages of the BST in improving sampling performance and in reducing adhesion and drag.
文摘为解决火力发电厂凝汽器压力不达标的问题,提出了凝汽器管束采用新型仿生布管形式,并用不锈钢管替代铜管的优化措施。系统投运测试表明:通过优化凝汽器管束布置方式,凝汽器压力降低了0.88 k Pa,过冷度小于0.5℃,凝汽器热力特性得到很大改善,主凝结区不存在涡流和空气积聚现象,机组可节约标准煤耗2.64 g/(k W·h),经济效益和环保效益显著。
