A new numerical method for determining collapse load-carrying capacity of structure made of elasto-plastic material  

作　　者：钟志鹏 任大龙 万水 

机构地区：[1]School of Transportation,Southeast University

出　　处：《Journal of Central South University》2014年第1期398-404,共7页中南大学学报（英文版）

基　　金：Project(2012CB026200)supported by the National Basic Research Program of China;Projects(50978055,50878048)supported by the National Natural Science Foundation of China

摘　　要：Determination of collapse load-carrying capacity of elasto-plastic material is very important in designing structure. The problem is commonly solved by elasto-plastic finite element method （FEM）. In order to deal with material nonlinear problem involving strain softening problem effectively, a new numerical method-damped Newton method was proposed. The iterative schemes are discussed in detail for pure equilibrium models. In the equilibrium model, the plasticity criterion and the compatibility of the strains are verified, and the strain increment and plastic factor are treated as independent unknowns. To avoid the stiffness matrix being singularity or condition of matrix being ill, a damping factor a was introduced to adjust the value of plastic consistent parameter automatically during the iterations. According to the algorithm, the nonlinear finite element program was complied and its numerical example was calculated. The numerical results indicate that this method converges very fast for both small load steps and large load steps. Compared with those results obtained by analysis and experiment, the predicted ultimate bearing capacity from the proposed method is identical.Determination of collapse load-carrying capacity of elasto-plastic material is very important in designing structure.The problem is commonly solved by elasto-plastic finite element method(FEM).In order to deal with material nonlinear problem involving strain softening problem effectively,a new numerical method-damped Newton method was proposed.The iterative schemes are discussed in detail for pure equilibrium models.In the equilibrium model,the plasticity criterion and the compatibility of the strains are verified,and the strain increment and plastic factor are treated as independent unknowns.To avoid the stiffness matrix being singularity or condition of matrix being ill,a damping factor α was introduced to adjust the value of plastic consistent parameter automatically during the iterations.According to the algorithm,the nonlinear finite element program was complied and its numerical example was calculated.The numerical results indicate that this method converges very fast for both small load steps and large load steps.Compared with those results obtained by analysis and experiment,the predicted ultimate bearing capacity from the proposed method is identical.

关 键 词：damped Newton method collapse load elasto-plastic material non-linear finite element method incremental-iterativeanalysis 

分 类 号：TB30[一般工业技术—材料科学与工程]