泡沫金属在双向承载条件下的力学性能

根据各向同性三维网状泡沫金属的简化结构模型,建立该类材料的双向拉伸力学分析模型.利用该力学模型推出泡沫金属在双向拉伸破坏时两向名义应力与孔率3者的数学关系式,并在此基础上进一步得出该类材料在承受双向载荷时的安全判据.当双向承受的名义应力相等时,还可得到泡沫金属在双向等荷承载条件下的载荷强度与孔率的数学关系.这些关系式通过泡沫镍为例的有关实验数据证明是相当实用的.而由本理论体系可得出对多孔体双向承载条件的安全性判断,这似乎是Gibson和Ashby的有关模型理论所未触及或难以做到的.

The Mechanical Property of Metal Foams under Biaxial Tension

A mechanical analytical model is put forward for the three-dimensional isotropic reticulated porous metals under biaxial tension according to a simplified structural model in this study. The relationship between biaxial nominal stresses and porosity at the beginning of breakdown is derived for these materials from this analytical model. Based on the resultant relationship, the safety criterion can be further obtained for these foamed metals under biaxial loading. When the biaxial nominal stresses are equal to each other, the mathematical relationship between loading strength and porosity can be also gained for the foamed metals under biaxial equal loads. According to the typical experiment on nickel foam as an example, it is proved that these theoretical formulas well accorded with the practical ones. The safety criterion for the porous bodies under biaxial loading can be gotten from this model, which is not dealt with or difficult to do by other relative theories, such as Gibson-Ashby model.