Theoretical prediction of effective elastic constants for new intermetallic compound porous material
(1. School of Civil Engineering, Central South University, Changsha 410075, China;
2. College of Civil Engineering and Mechanics, Central South University of Forestry and Technology,Changsha 410004, China;
3. Powder Metallurgy Research Institute, Central South University, Changsha 410083, China)
2. College of Civil Engineering and Mechanics, Central South University of Forestry and Technology,Changsha 410004, China;
3. Powder Metallurgy Research Institute, Central South University, Changsha 410083, China)
Abstract: Based on microstructure analysis of the new Ti-Al intermetallic compound porous material, a micromechanics model of heterogeneous Plateau porous structure was established and calculation formulas of elastic constants (including effective elastic modulus, effective shear elastic modulus and effective Poisson ratio) were derived by the energy method for this porous material. Calculation results show that both the effective elastic modulus and effective shear elastic modulus increase with the increase of the relative density while the effective Poisson ratio decreases. Compared with the currently-existing hexagonal honeycomb model and micromechanics model of composite materials, the micromechanics model of heterogeneous Plateau porous structure in this study is more suitable for characterizing the medium-density porous material and more accurate for predicting the effective elastic constants of the medium-density porous material. Moreover, the obtained explicit expressions of the effective elastic constants in term of the relative density rather than the microstructural parameters for the uniform and regular Plateau porous structure are more convenient to engineering application.
Key words: intermetallic compound; porous material; effective elastic modulus; Plateau structure; energy method