动车组牵引系统是动力核心,确保“一次设计正确”是在复杂牵引系统研制过程中面临的首要任务,传统的基于文档的设计方式已不能满足当前牵引系统“任务重、周期短、质量要求高”的研制需求。文章以某动车组牵引系统为研究对象,运用基于...动车组牵引系统是动力核心,确保“一次设计正确”是在复杂牵引系统研制过程中面临的首要任务,传统的基于文档的设计方式已不能满足当前牵引系统“任务重、周期短、质量要求高”的研制需求。文章以某动车组牵引系统为研究对象,运用基于模型的系统工程(model-based systems engineering,MBSE)方法,创建了系统的需求模型、功能模型、架构模型、功能需求的验证模型,并创建了基于多学科综合验证的性能验证模型、三维数字样机模型,运用数字化手段在详细设计开展之前完成了方案设计阶段的需求捕获、分析及验证,将发现问题和实物验证阶段前移至了方案设计阶段,大幅度缩短了后续的设计迭代周期,降低了设计成本。展开更多
Repeated Unit Cell（RUC）is a useful tool in micromechanical analysis of composites using Displacement-based Finite Element（DFE）method,and merely applying Periodic Displacement Boundary Conditions（PDBCs）to RUC is ...Repeated Unit Cell（RUC）is a useful tool in micromechanical analysis of composites using Displacement-based Finite Element（DFE）method,and merely applying Periodic Displacement Boundary Conditions（PDBCs）to RUC is almost a standard practice to conduct such analysis.Two basic questions arising from this practice are whether Periodic Traction Boundary Conditions（PTBCs,also known as traction continuity conditions）are guaranteed and whether the solution is independent of selection of RUCs.This paper presents the theoretical aspects to tackle these questions,which unify the strong form,weak form and DFE method of the micromechanical problem together.Specifically,the solution’s independence of selection of RUCs is dealt with on the strong form side,PTBCs are derived from the weak form as natural boundary conditions,and the validity of merely applying PDBCs in micromechanical Finite Element（FE）analysis is proved by referring to its intrinsic connection to the strong form and weak form.Key points in the theoretical aspects are demonstrated by illustrative examples,and the merits of setting micromechanical FE analysis under the background of a clear theoretical framework are highlighted in the efficient selection of RUCs for Uni Directional（UD）fiber-reinforced composites.展开更多
文摘动车组牵引系统是动力核心,确保“一次设计正确”是在复杂牵引系统研制过程中面临的首要任务,传统的基于文档的设计方式已不能满足当前牵引系统“任务重、周期短、质量要求高”的研制需求。文章以某动车组牵引系统为研究对象,运用基于模型的系统工程(model-based systems engineering,MBSE)方法,创建了系统的需求模型、功能模型、架构模型、功能需求的验证模型,并创建了基于多学科综合验证的性能验证模型、三维数字样机模型,运用数字化手段在详细设计开展之前完成了方案设计阶段的需求捕获、分析及验证,将发现问题和实物验证阶段前移至了方案设计阶段,大幅度缩短了后续的设计迭代周期,降低了设计成本。
文摘Repeated Unit Cell（RUC）is a useful tool in micromechanical analysis of composites using Displacement-based Finite Element（DFE）method,and merely applying Periodic Displacement Boundary Conditions（PDBCs）to RUC is almost a standard practice to conduct such analysis.Two basic questions arising from this practice are whether Periodic Traction Boundary Conditions（PTBCs,also known as traction continuity conditions）are guaranteed and whether the solution is independent of selection of RUCs.This paper presents the theoretical aspects to tackle these questions,which unify the strong form,weak form and DFE method of the micromechanical problem together.Specifically,the solution’s independence of selection of RUCs is dealt with on the strong form side,PTBCs are derived from the weak form as natural boundary conditions,and the validity of merely applying PDBCs in micromechanical Finite Element（FE）analysis is proved by referring to its intrinsic connection to the strong form and weak form.Key points in the theoretical aspects are demonstrated by illustrative examples,and the merits of setting micromechanical FE analysis under the background of a clear theoretical framework are highlighted in the efficient selection of RUCs for Uni Directional（UD）fiber-reinforced composites.
