The paper is to design and construct a coupled elasto-plasticity damage constitutive model for concrete.Based on the energy dissipation principle,the Hsieh-Ting-Chen four-parameter yield function is used.The model can...The paper is to design and construct a coupled elasto-plasticity damage constitutive model for concrete.Based on the energy dissipation principle,the Hsieh-Ting-Chen four-parameter yield function is used.The model can reflect different strength characteristics of concrete in tension and compression,and reduce the limitation and lacuna of the traditional damage constitutive models for concrete.Furthermore,numerical test for concrete stress-strain relation under uniaxial tension and compression is given.Moreover,the damage process of concrete gravity dam is calculated and analyzed in seismic load.Compared with other damage constitutive models,the proposed model contains only one unknown parameter and the other parameters can be found in the Hsieh-Ting-Chen four-parameter yield function.The same damage evolution law,which is used for tension and compression,is good for determining stress-strain constitutive and damage characteristics in complex stress state.This coupled damage constitutive models can be applied in analyzing damage of concrete gravity dam and arch dam.展开更多
为实现多组分复杂流体流动与扩散耦合过程的准确预测,提出一种耦合多组分Shan-Chen格子玻尔兹曼法(lattice Boltzmann method,LBM)、Maxwell-Stefan扩散通量方程及4参数(临界温度、临界压力、偏心因子和体积修正因子)Peng-Robinson状态...为实现多组分复杂流体流动与扩散耦合过程的准确预测,提出一种耦合多组分Shan-Chen格子玻尔兹曼法(lattice Boltzmann method,LBM)、Maxwell-Stefan扩散通量方程及4参数(临界温度、临界压力、偏心因子和体积修正因子)Peng-Robinson状态方程(equation of state,EOS)的多组分流体流动与扩散耦合模型(equation of state Maxwell-Stefan force model,EOS-MS模型).通过Peng-Robinson EOS计算混合流体整体的流体间作用力,结合多组分LBM中流体间作用力与压力的关系,构建组分流速与流体间作用力的关联,并代入Maxwell-Stefan方程,推导得到各组分受力的代数方程组.利用精确差分法(exact difference method,EDM)将计算得到的组分间作用力引入多组分LBM.分别模拟甲烷、乙烷纯物质及其混合物的气液两相共存问题,计算结果与标准参考数据及逸度平衡法的计算结果一致,验证了模型在预测混合流体热力学平衡态方面的准确性.通过模拟氢气、氮气和二氧化碳的三元扩散动态过程,发现模型结果与有限体积法预测高度吻合,并成功复现了多组分流体中逆扩散等实际扩散现象,证明模型在多组分流体流动与扩散耦合模拟中的有效性.本研究构建的EoS-MS力模型可准确预测多组分流动与扩散耦合过程,避免了在组分受力计算中引入人为假设带来的误差,为解决地热资源利用等领域中存在的多组分复杂流动问题提供了新方法.展开更多
基金Project supported by the National Natural Science Foundation of China(Nos.51109029,51178081,51138001 and 51009020)the China Postdoctoral Science Foundation(No.20110491535)the State Key Development Program for Basic Research of China (No.2013CB035905)
文摘The paper is to design and construct a coupled elasto-plasticity damage constitutive model for concrete.Based on the energy dissipation principle,the Hsieh-Ting-Chen four-parameter yield function is used.The model can reflect different strength characteristics of concrete in tension and compression,and reduce the limitation and lacuna of the traditional damage constitutive models for concrete.Furthermore,numerical test for concrete stress-strain relation under uniaxial tension and compression is given.Moreover,the damage process of concrete gravity dam is calculated and analyzed in seismic load.Compared with other damage constitutive models,the proposed model contains only one unknown parameter and the other parameters can be found in the Hsieh-Ting-Chen four-parameter yield function.The same damage evolution law,which is used for tension and compression,is good for determining stress-strain constitutive and damage characteristics in complex stress state.This coupled damage constitutive models can be applied in analyzing damage of concrete gravity dam and arch dam.
文摘为实现多组分复杂流体流动与扩散耦合过程的准确预测,提出一种耦合多组分Shan-Chen格子玻尔兹曼法(lattice Boltzmann method,LBM)、Maxwell-Stefan扩散通量方程及4参数(临界温度、临界压力、偏心因子和体积修正因子)Peng-Robinson状态方程(equation of state,EOS)的多组分流体流动与扩散耦合模型(equation of state Maxwell-Stefan force model,EOS-MS模型).通过Peng-Robinson EOS计算混合流体整体的流体间作用力,结合多组分LBM中流体间作用力与压力的关系,构建组分流速与流体间作用力的关联,并代入Maxwell-Stefan方程,推导得到各组分受力的代数方程组.利用精确差分法(exact difference method,EDM)将计算得到的组分间作用力引入多组分LBM.分别模拟甲烷、乙烷纯物质及其混合物的气液两相共存问题,计算结果与标准参考数据及逸度平衡法的计算结果一致,验证了模型在预测混合流体热力学平衡态方面的准确性.通过模拟氢气、氮气和二氧化碳的三元扩散动态过程,发现模型结果与有限体积法预测高度吻合,并成功复现了多组分流体中逆扩散等实际扩散现象,证明模型在多组分流体流动与扩散耦合模拟中的有效性.本研究构建的EoS-MS力模型可准确预测多组分流动与扩散耦合过程,避免了在组分受力计算中引入人为假设带来的误差,为解决地热资源利用等领域中存在的多组分复杂流动问题提供了新方法.
