Under the frame of multibody dynamics, the contact dynamics of elasto-plastic spatial thin beams is numerically studied by using the spatial thin beam elements of absolute nodal coordinate formulation(ANCF). The int...Under the frame of multibody dynamics, the contact dynamics of elasto-plastic spatial thin beams is numerically studied by using the spatial thin beam elements of absolute nodal coordinate formulation(ANCF). The internal force of the elasto-plastic spatial thin beam element is derived under the assumption that the plastic strain of the beam element depends only on its longitudinal deformation.A new body-fixed local coordinate system is introduced into the spatial thin beam element of ANCF for efficient contact detection in the contact dynamics simulation. The linear isotropic hardening constitutive law is used to describe the elasto-plastic deformation of beam material, and the classical return mapping algorithm is adopted to evaluate the plastic strains. A multi-zone contact approach of thin beams previously proposed by the authors is also introduced to detect the multiple contact zones of beams accurately, and the penalty method is used to compute the normal contact force of thin beams in contact. Four numerical examples are given to demonstrate the applicability and effectiveness of the proposed elasto-plastic spatial thin beam element of ANCF for flexible multibody system dynamics.展开更多
Change is a word synonymous with China. Since inaugurating its reform campaign 29 years ago, the nation has seen countless examples of change, from the social, economic, political and cultural perspectives. Many of th...Change is a word synonymous with China. Since inaugurating its reform campaign 29 years ago, the nation has seen countless examples of change, from the social, economic, political and cultural perspectives. Many of these changes have been dramatic and have spawned social problems and related disputes. The 21st Century Business Herald, a leading Chinese financial news- paper, recently convened a group of eminent scholars specializing in social sciences to discuss the challenges facing China's further reform and the trend of its social development. Professor Zhou Weimin, Editor in Chief of Study Times, Yang Fengchun, Dean of the E-Government Research Center of Peking University, Professor Mao Shoulong, Faculty Director of the Department of Public Administration of the Renmin University of China, and Professor Zhen Xiaoying at the Central Institute of Socialism, give their opinions in the following excerpts:展开更多
基金supported in part by the National Natural Science Foundation of China (Grants 11290151 and 11221202)supported in part by the Beijing Higher Education Young Elite Teacher Project (Grant YETP1201)
文摘Under the frame of multibody dynamics, the contact dynamics of elasto-plastic spatial thin beams is numerically studied by using the spatial thin beam elements of absolute nodal coordinate formulation(ANCF). The internal force of the elasto-plastic spatial thin beam element is derived under the assumption that the plastic strain of the beam element depends only on its longitudinal deformation.A new body-fixed local coordinate system is introduced into the spatial thin beam element of ANCF for efficient contact detection in the contact dynamics simulation. The linear isotropic hardening constitutive law is used to describe the elasto-plastic deformation of beam material, and the classical return mapping algorithm is adopted to evaluate the plastic strains. A multi-zone contact approach of thin beams previously proposed by the authors is also introduced to detect the multiple contact zones of beams accurately, and the penalty method is used to compute the normal contact force of thin beams in contact. Four numerical examples are given to demonstrate the applicability and effectiveness of the proposed elasto-plastic spatial thin beam element of ANCF for flexible multibody system dynamics.
文摘Change is a word synonymous with China. Since inaugurating its reform campaign 29 years ago, the nation has seen countless examples of change, from the social, economic, political and cultural perspectives. Many of these changes have been dramatic and have spawned social problems and related disputes. The 21st Century Business Herald, a leading Chinese financial news- paper, recently convened a group of eminent scholars specializing in social sciences to discuss the challenges facing China's further reform and the trend of its social development. Professor Zhou Weimin, Editor in Chief of Study Times, Yang Fengchun, Dean of the E-Government Research Center of Peking University, Professor Mao Shoulong, Faculty Director of the Department of Public Administration of the Renmin University of China, and Professor Zhen Xiaoying at the Central Institute of Socialism, give their opinions in the following excerpts: