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通过引入与Batra及Kim类似的观点,将绝热剪切带宽度定义为绝热剪切带的中心区域的宽度(w5%),在该区域上温度比其峰值小5%,利用Johnson-Cook模型及梯度塑性理论分析Ti-6Al-4V绝热剪切带的厚度随环境温度的演变规律。计算表明,随着环境温度的升高,绝热剪切带宽度增加,这与许多实验观测结果一致。当绝热剪切带的总厚度在上限时,绝热剪切带宽度-环境温度曲线是稍微上凹的;但是,当绝热剪切带的总厚度在下限时,绝热剪切带宽度-环境温度曲线基本上是直线,著名的Dodd及Bai模型无法预测这些新现象。关于绝热剪切带宽度的计算结果非常接近于Liao及Duffy的实测结果。在忽略应变硬化的条件下,采用线性软化模型及梯度塑性理论推导w5%的简化解析式,发现环境温度、密度、热容、软化模量、剪切应力的增加使绝热剪切的敏感性降低,而功热转化因子及抗剪强度的降低使绝热剪切的敏感性降低。
By introducing a similar view to Batra and Kim, the adiabatic shear band width is defined as the width (w5%) of the central region of the adiabatic shear band where the temperature is 5% less than its peak value. Using the Johnson-Cook model and Gradient plasticity theory is used to analyze the evolution of the thickness of Ti-6Al-4V adiabatic shear band with the ambient temperature. Calculations show that as the ambient temperature increases, the adiabatic shear band width increases, consistent with many experimental observations. When the total thickness of the adiabatic shear band is at the upper limit, the adiabatic shear band width-ambient temperature curve is slightly concave; however, when the total thickness of the adiabatic shear band is at the lower limit, the adiabatic shear band width-ambient temperature curve is substantially On the straight line, the famous Dodd and Bai models can not predict these new phenomena. The calculation of the adiabatic shear band width is very close to the actual measurements of Liao and Duffy. By neglecting strain hardening, the linearized softening model and the gradient plasticity theory are used to derive a simplified analytic formula of w5%. It is found that the increase of ambient temperature, density, heat capacity, softening modulus and shear stress decreases the sensitivity of adiabatic shear , While the reduction of heat-transfer factor and shear strength decreases the sensitivity of adiabatic shear.