A new multi-level analysis method of introducing the super-element modeling method, derived from the multi-level analysis method first proposed by O. F. Hughes, has been proposed in this paper to solve the problem of ...A new multi-level analysis method of introducing the super-element modeling method, derived from the multi-level analysis method first proposed by O. F. Hughes, has been proposed in this paper to solve the problem of high time cost in adopting a rational-based optimal design method for ship structural design. Furthermore,the method was verified by its effective application in optimization of the mid-ship section of a container ship. A full 3-D FEM model of a ship,suffering static and quasi-static loads, was used as the analyzing object for evaluating the structural performance of the mid-ship module, including static strength and buckling performance. Research results reveal that this new method could substantially reduce the computational cost of the rational-based optimization problem without decreasing its accuracy, which increases the feasibility and economic efficiency of using a rational-based optimal design method in ship structural design.展开更多
The characteristic properties of shell element with similar shapes are used to generate a so-called super element for the analysis of the crack problems for cylindrical pressure vessels. The formulation is processed b...The characteristic properties of shell element with similar shapes are used to generate a so-called super element for the analysis of the crack problems for cylindrical pressure vessels. The formulation is processed by matrix condensation without the involvement of special treatment. This method can deal with various singularity problems and it also presents excellent results to crack problems for cylindrical shell. Especially,the knowledge of the kind of singular order is not necessary in super element generation; it is very economical in terms of computer memory and programming. This method also exhibits versatility to solve the problem of kinked crack at cylindrical shell.展开更多
Advanced manufacturing processes such as additive manufacturing offer now the capability to control material placement at unprecedented length scales and thereby dramatically open up the design space.This includes the...Advanced manufacturing processes such as additive manufacturing offer now the capability to control material placement at unprecedented length scales and thereby dramatically open up the design space.This includes the considerations of new component topologies as well as the architecture of material within a topology offering new paths to creating lighter and more efficient structures.Topology optimization is an ideal tool for navigating this multiscale design problem and leveraging the capabilities of advanced manufacturing technologies.However,the resulting design problem is computationally challenging as very fine discretizations are needed to capture all micro-structural details.In this paper,a method based on reduction techniques is proposed to perform efficiently topology optimization at multiple scales.This method solves the design problem without length scale separation,i.e.,without iterating between the two scales.Ergo,connectivity between space-varying micro-structures is naturally ensured.Several design problems for various types of micro-structural periodicity are performed to illustrate the method,including applications to infill patterns in additive manufacturing.展开更多
基金Supported by the Project of Ministry of Education and Finance(No.200512)the Project of the State Key Laboratory of ocean engineering(GKZD010053-10)
文摘A new multi-level analysis method of introducing the super-element modeling method, derived from the multi-level analysis method first proposed by O. F. Hughes, has been proposed in this paper to solve the problem of high time cost in adopting a rational-based optimal design method for ship structural design. Furthermore,the method was verified by its effective application in optimization of the mid-ship section of a container ship. A full 3-D FEM model of a ship,suffering static and quasi-static loads, was used as the analyzing object for evaluating the structural performance of the mid-ship module, including static strength and buckling performance. Research results reveal that this new method could substantially reduce the computational cost of the rational-based optimization problem without decreasing its accuracy, which increases the feasibility and economic efficiency of using a rational-based optimal design method in ship structural design.
基金Project (No. NSC-95-2221-E-167-002) supported by the National Science Council of Taiwan, China
文摘The characteristic properties of shell element with similar shapes are used to generate a so-called super element for the analysis of the crack problems for cylindrical pressure vessels. The formulation is processed by matrix condensation without the involvement of special treatment. This method can deal with various singularity problems and it also presents excellent results to crack problems for cylindrical shell. Especially,the knowledge of the kind of singular order is not necessary in super element generation; it is very economical in terms of computer memory and programming. This method also exhibits versatility to solve the problem of kinked crack at cylindrical shell.
基金This research was supported in part by the US National Science Foundation(NSF)under Grant Number 1462453in part by the National Aeronautics and Space Administration(NASA)under Grant Number 80NSSC18K0428.Any opinions,findings,and conclusions or recommendations expressed in this article are those of the author(s)and do not necessarily reflect the views of NSF or NASA.
文摘Advanced manufacturing processes such as additive manufacturing offer now the capability to control material placement at unprecedented length scales and thereby dramatically open up the design space.This includes the considerations of new component topologies as well as the architecture of material within a topology offering new paths to creating lighter and more efficient structures.Topology optimization is an ideal tool for navigating this multiscale design problem and leveraging the capabilities of advanced manufacturing technologies.However,the resulting design problem is computationally challenging as very fine discretizations are needed to capture all micro-structural details.In this paper,a method based on reduction techniques is proposed to perform efficiently topology optimization at multiple scales.This method solves the design problem without length scale separation,i.e.,without iterating between the two scales.Ergo,connectivity between space-varying micro-structures is naturally ensured.Several design problems for various types of micro-structural periodicity are performed to illustrate the method,including applications to infill patterns in additive manufacturing.
