Void Nucleation and Growth for Elastic Solid Materials
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摘要: 建立了描述彈性固體材料中空穴萌生與增長的非線性數學模型,獲得了空穴萌生時控制參數臨界值的精確計算公式和空穴半徑增長的精確表達式.在大變形幾何分析中采用了對數應變度量,并且應用了Hooke彈性固體材料的本構關系.數值分析結果表明:當材料不可壓時空穴萌生的臨界載荷將略低于neo-Hooke不可壓超彈性材料的相應計算結果,并且在空穴萌生后空穴半徑將迅速增大,這與細觀損傷力學和超彈性材料的空穴分叉理論的結論相一致;空穴萌生時環向應力將成為無限大;如果材料是彈塑性(韌性)材料,則會使得空穴附近發生塑性變形,從而導致材料的局部損傷和破壞.Abstract: The nonlinear mathematical model is given to describe void nucleation and growth for elastic solid materials. Exact formulae to calculate the critical values of control parameters for cavitation and exact expressions for growth of void radial are derived. For large deformation, finite logarithmic strain measure is used, and the constitutive relationship of materials is basic on Hookean elastic law. The numerical results show that the critical loads of cavitation for Hooke elastic solid in the case of uncompressible materials are slightly lower than the critical loads for uncompressible neo-Hookean hyperelastic materials. The cavity will be suddenly ra-pid growth after void nucleation. This conclusion is agreed with the corresponding conclusion from the damage micromechanics and the theory of cavitated bifurcation for hyperelastic materials. Also, the analysis shows that the loop stress will become infinite when void nucleation. Thus, the materials near the cavity will product plastic deformation if the materials are elastic-plastic. This leads to local failure and fracture of the materials.
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