基于微极理论的新型FeAl多孔材料弹性模量研究

Elastic modulus for new FeAl porous material based on micropolar theory

针对本课题组制备的一种新型金属间化合物多孔材料即FeAl多孔材料,分析其孔隙结构的微观特征,建立六边形多孔结构模型,利用微极理论和能量法推导出多孔材料弹性模量的理论计算公式,并通过单轴拉伸实验加以验证。研究结果表明:多孔材料的相对弹性模量E_1/E_s随相对密度ρ~*/ρ_s增加而增大,且弯曲剪力对E_1/E_s的影响也随之增大,故中、高密度的多孔材料必须考虑弯曲剪力对E_1/E_s的影响;采用能量法精确计算微极弹性连续介质的结构位移,且考虑弯曲剪力对相对弹性模量的影响,理论公式计算的弹性模量更接近于实验结果,从而验证了弹性模量理论公式更加准确、可靠。

A new type of intermetallic porous material,FeAl porous material,was prepared by our research group.A hexagonal pore structure model was established by analyzing its pore microstructure characteristics and a new calculation formula of elastic modulus was derived by micropolar theory and energy method for FeAl porous,and moreover,the calculation formula was verified by uniaxial tensile test.The results show that the relative elastic modulus E1/Es increases with the increase of the relative densityρ*/ρs,and the effect of bending shear force on E1/Es also increases,so the shear force must be considered for the medium and high density porous material.The energy method is adopted to calculate exactly displacements of micropolar elastic continuum and the effect of bending shear force on elastic modulus is considered,and therefore,the theoretical value of elastic modulus in this study is closer to its experimental value and more accurate and reliable.