【摘要】 利用分离式Hopkinson压杆实验设备测定了4种航空铝合金材料的动态力学性能,根据材料的应力应变曲线特性,选择Cowper-Symonds模型来拟合4种材料的动态本构.在此基础上从实验结果中分析和比较了这4种铝合金在动态冲击下的破坏形式和动态力学特性.实验结果表明LF6R和LF21M具有良好的塑性,而LY12CZ和LC4CS具有一定的脆性;随着4种材料屈服应力的提高,材料切线模量也增加,二者呈线性关系;实验的4种航空铝材中LC4CS应变率敏感程度最小,LF6R敏感程度最大,LF21M,LY12CZ和LC4CS的应变率因子曲线形状相同.更多还原

【Abstract】 Dynamic mechanical properties of four aluminum alloy were attained with the split Hopkinson pressure bar(SHPB) apparatus.According to the characters of the stress-strain curves,the Cowper-Symonds constitutive model was chosen and its relationship parameters were fitted according to the experiment data.The failure modes and their dynamic mechanical properties were compared among the four materials.The results show that LF6R and LF21M have good plasticity,LY12CZ and LC4CS have some brittleness.The tangent modulus linearly increase with yield stress.Among the four experimented aluminum-alloy materials,the strain-rate sensitivity of LC4CS is minimum;the strain-rate sensitivity of LF6R is maximum;the strain-rate sensitivity curves of LF21M,LY12CZ and LC4CS have the same shape.更多还原