对于含切口简支梁受均布荷载作用的问题,基于Williams应力函数,通过边界配置法并借用无裂纹体应力边界条件,求得了含高阶项的全场解析解及相应的应力强度因子K_Ⅰ。基于"Duan and Nakagawa’s"模型,通过对首项(奇异项)进行加...对于含切口简支梁受均布荷载作用的问题,基于Williams应力函数,通过边界配置法并借用无裂纹体应力边界条件,求得了含高阶项的全场解析解及相应的应力强度因子K_Ⅰ。基于"Duan and Nakagawa’s"模型,通过对首项(奇异项)进行加权积分,消除了裂缝尖端应力呈无穷大的奇异性,得到了内聚区模型的全场解析解。通过对不同解法下典型截面正应力分布的比较,表明内聚区模型解消除了裂缝尖端应力的奇异性,比函数叠加法的结果精度更高,这样的数学力学模型可以从宏观上反映混凝土类材料的断裂特性。展开更多
In order to investigate the fatigue behavior of asphalt concrete, a new numerical approach based on a bi-linear cohesive zone model （CZM） is developed. Integrated with the CZM, a fatigue damage evolution model is es...In order to investigate the fatigue behavior of asphalt concrete, a new numerical approach based on a bi-linear cohesive zone model （CZM） is developed. Integrated with the CZM, a fatigue damage evolution model is established to indicate the gradual degradation of cohesive properties of asphalt concrete under cyclic loading. Then the model is implemented in the finite element software ABAQUS through a user-defined subroutine. Based on the proposed model, an indirect tensile fatigue test is finally simulated. The fatigue lives obtained through numerical analysis show good agreement with laboratory results. Fatigue damage accumulates in a nonlinear manner during the cyclic loading process and damage initiation phase is the major part of fatigue failure. As the stress ratio increases, the time of the steady damage growth stage decreases significantly. It is found that the proposed fatigue damage evolution model can serve as an accurate and efficient tool for the prediction of fatigue damage of asphalt concrete.展开更多
A cohesive zone model is employed to simulate the fiber/matrix interface damage of composites with ductile matrix. The study is carried out to investigate the dependence of the interface damage and the composite tensi...A cohesive zone model is employed to simulate the fiber/matrix interface damage of composites with ductile matrix. The study is carried out to investigate the dependence of the interface damage and the composite tensile strength on the micro parameters of the composite. These parameters contain fiber packing pattern, fiber volume fraction, and the modulus ratio of the fiber to the matrix. The investigation reveals that though the high fiber vo lume fraction, the high fiber′s modulus and the square fiber packing can supply strong reinforcement to the composite, the interface damage is susceptible in these cases. The tensile strength of the composite is dominated by the interface strength when the interface debonding occurs.展开更多
文摘对于含切口简支梁受均布荷载作用的问题,基于Williams应力函数,通过边界配置法并借用无裂纹体应力边界条件,求得了含高阶项的全场解析解及相应的应力强度因子K_Ⅰ。基于"Duan and Nakagawa’s"模型,通过对首项(奇异项)进行加权积分,消除了裂缝尖端应力呈无穷大的奇异性,得到了内聚区模型的全场解析解。通过对不同解法下典型截面正应力分布的比较,表明内聚区模型解消除了裂缝尖端应力的奇异性,比函数叠加法的结果精度更高,这样的数学力学模型可以从宏观上反映混凝土类材料的断裂特性。
基金The Open Research Fund of Key Laboratory of Highway Engineering of Sichuan Province of Southw est Jiaotong University (No.LHTE002201102)
文摘In order to investigate the fatigue behavior of asphalt concrete, a new numerical approach based on a bi-linear cohesive zone model （CZM） is developed. Integrated with the CZM, a fatigue damage evolution model is established to indicate the gradual degradation of cohesive properties of asphalt concrete under cyclic loading. Then the model is implemented in the finite element software ABAQUS through a user-defined subroutine. Based on the proposed model, an indirect tensile fatigue test is finally simulated. The fatigue lives obtained through numerical analysis show good agreement with laboratory results. Fatigue damage accumulates in a nonlinear manner during the cyclic loading process and damage initiation phase is the major part of fatigue failure. As the stress ratio increases, the time of the steady damage growth stage decreases significantly. It is found that the proposed fatigue damage evolution model can serve as an accurate and efficient tool for the prediction of fatigue damage of asphalt concrete.
文摘A cohesive zone model is employed to simulate the fiber/matrix interface damage of composites with ductile matrix. The study is carried out to investigate the dependence of the interface damage and the composite tensile strength on the micro parameters of the composite. These parameters contain fiber packing pattern, fiber volume fraction, and the modulus ratio of the fiber to the matrix. The investigation reveals that though the high fiber vo lume fraction, the high fiber′s modulus and the square fiber packing can supply strong reinforcement to the composite, the interface damage is susceptible in these cases. The tensile strength of the composite is dominated by the interface strength when the interface debonding occurs.
