Yield surface of transversely isotropic foams under axisymmetric loadings
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摘要: 利用二维有效应力和平均应力的描述方法,推导出三维横观各向同性泡沫材料在轴对称载荷下的特征平均应力、特征应力以及特征应变的表达式,得到用特征平均应力和特征应力描述的屈服面模型;并通过对面心立方单胞模型进行有限元分析,研究了横观各向同性泡沫材料的泡孔长径比对弹性性能和屈服面的影响.结果表明:随泡孔长径比的增加,泡孔伸长方向对应的泡沫模量增加,而与其垂直方向的泡沫模量则减小,且屈服面发生了逆时针转动;得到的屈服面模型与Gurson修正模型基本一致,且同有限元结果相符,为横观各向同性泡沫提供了一种新的屈服面描述.Abstract: The effective stress and mean stress description method for two-dimension (2D) materials was applied to obtain the formulae of characteristic mean stress, characteristic stress, and characteristic strain of three-dimension (3D) transversely isotropic materials under proportional axisymmetric loadings. Then the yield surface model expressed by characteristic mean stress and characteristic stress was established. Through the analysis of transversely isotropic face-centered cubic unit cell model by using finite-element method (FEM), the impact of cell aspect ratio on the elastic properties and the yield surface for transversely isotropic foams was also investigated. The results show that the increase of cell aspect ratio leads to the augment of longitudinal modulus, the decrease of transverse modulus and the anticlockwise rotation of yield surface. The model corresponds well with the modified Gurson-s model and the FEM results, and thus provides a new description for 3D transversely isotropic foams- yield surface.
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Key words:
- foams /
- yield /
- finite element method
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[1] Gibson L J,Ashby M F.Cellular solids:Structures & properties[M].Cambridge:Cambridge University Press,1997 [2] 卢子兴,郭宇.金属泡沫材料力学行为的研究概述[J].北京航空航天大学学报,2003,29(1):978-983 Lu Zixing,Guo Yu.Brief review of studies on the mechanical behavior of metallic foams[J].Journal of Beijing University of Aeronautics and Astronautics,2003,29(1):978-983 (in Chinese) [3] Deshpande V S,Fleck N A.Isotropic constitutive models for metallic foams[J].Journal of the Mechanics and Physics of Solids,2000,48(6):1253-1283 [4] Deshpande V S,Fleck N A.Multi-axial yield behaviour of polymer foams[J].Acta Materialia,2001,49(10):1859-1866 [5] Chen C,Lu T J.A phenomenological framework of constitutive modeling for incompressible and compressible elasto-plastic solids[J].International Journal of Solids and Structures,2000,37(52):7769-7786 [6] Tvergaard V.Influence of void nucleation on ductile shear fracture at a free surface [J].Journal of the Mechanics and Physics of Solids,1982,30(6):399-425 [7] Gioux G,Mccormack T M,Gibson L J.Failure of aluminum foams under multiaxial loads [J].International Journal of Mechanical Sciences,2000,42(6):1097-1117 [8] Tagarielli V L,Deshpande V S,Fleck N A,et al.A constitutive model for transversely isotropic foams,and its application to the indentation of balsa wood [J].International Journal of Mechanical Science,2005,47(4/5):666-686 [9] Alkhader M,Vura M.An energy-based anisotropic yield criterion for cellular solids and validation by biaxial FE simulations[J].Journal of the Mechanics and Physics of Solids,2009,57(5):871-890 [10] 袁本立,卢子兴.基于三类单胞模型的开、闭孔泡沫材料弹性性能的有限元分析[J].机械强度,2007,29(4):627-631 Yuan Benli,Lu Zixing.Finite element analysis of elastic properties of open-cell and closed-cell foam based on three kind of cell models[J].Journal of Mechanical Strength,2007,29(4):627-631(in Chinese)
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