基于能量法的多孔材料抗拉强度预测模型  

Prediction model of effective tensile strength of porous materials based on energy method

作　　者：李泽前 李宗利 尚洪彬[1] 杨霖 LI Zeqian;LI Zongli;SHANG Hongbin;YANG Lin(College of Water Resources and Architectural Engineering,Northwest A&F University,Xianyang 712100,China;Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas of Ministry of Education,Northwest A&F University,Xianyang 712100,China)

机构地区：[1]西北农林科技大学水利与建筑工程学院,陕西咸阳712100 [2]西北农林科技大学旱区农业水土工程教育部重点实验室,陕西咸阳712100

出　　处：《混凝土》2024年第4期41-46,共6页Concrete

基　　金：国家自然科学基金(51379178)。

摘　　要：将多孔材料缺陷简化为空心球,运用弹性力学的基本知识,基于能量法建立不同缺陷含量的多孔材料与材料基质极限应变能密度之间的关系,结合多孔材料的破坏假定和最大拉应力准则,推导了不同缺陷含量的多孔材料的抗拉强度。采用孔径结构影响系数来考虑孔径分布的影响,对抗拉强度预测模型进行修正。预测模型与试验结果和经典的多孔材料强度预测模型进行对比,并分析了泊松比和孔径分布对其影响规律。结果表明:建立的抗拉强度预测模型的预测值和试验结果吻合较好。不考虑孔径分布影响时,文中模型与经典模型有良好的一致性;泊松比对抗强度的影响随着孔隙率的增大而增大。抗拉强度同时受到总孔隙率和孔径分布的影响,随孔隙率的增大而减小;孔隙率一定时,小孔径含量越多,抗拉强度越大。The porous materials with different defect is simplified as a hollow sphere.Based on the basic knowledge of elastic mechan-ics,the relationship between the limit strain energy density of porous materials with different defect contents and the material matrix is es-tablished by using the energy method,the tensile strength of porous materials with different defect contents is derived by combining the as-sumption of failure and the criterion of maximum tensile stress.Considering the influence of pore size distribution,the influence coefficient of pore size structure is used to modify the prediction model of tensile strength.The prediction model was compared with the experimental results and the classical strength prediction model for porous materials,and the influence of Poisson's ratio and pore size distribution on the strength of porous materials was analyzed.The results show that the predicted values of the tensile strength model established are in good a-greement with the experimental results.When the effect of pore size distribution is not considered,the model is in good agreement with the classical model,and the extent of influence of Poisson's ratio on the resistance strength increases with the increase of porosity.The tensile strength is affected by both total porosity and pore size distribution,and decreases with the increase of porosity.

关 键 词：多孔材料 抗拉强度 能量法 空心球 孔隙率 孔径分布 

分 类 号：TU528.041[建筑科学—建筑技术科学]