N metallic materials - sheet and strip - determination of tensile strain hardening exponent n - values 金属薄板和薄带拉伸应变硬化指数
Iron and steel - method of determination of the tensile strain hardening exponent n of steel sheet and plate 钢铁.薄钢板和钢板拉伸应变硬化指数n的测定方法
By analyzing the simulation results , how the hardening parameter , bend radius parameter and thickness parameter influence springback is studied 通过对模拟结果的分析,研究了硬化指数、弯曲半径、材料厚度等因素对回弹的影响规律。
Research and expound in detail the vascular stiffness index ( vsi ) measurement , and apply it to the clinical test to verify , analyse and improve 深入研究和详细阐述了血管硬化指数这一参数测量方法,并在临床测试中进行验证、归纳和改进。
The springback angle increases with the increase of the punch round radius and clearances between the punch and the die while decreases with increase of the blank holder force , sheet thickness , friction coefficient and material hardening exponent 回弹角随凸模圆角半径和凸凹模间隙的增大而增大,随压边力、板料厚度、摩擦系数和材料硬化指数的增大而减小。
Fatigue strength coefficient decreases linearly during the cyclic course ; fatigue strength exponent increases ; fatigue ductility coefficient first goes up till the maximum value at 50 % total life , and then goes down ; fatigue ductility exponent decreases during the first half cycle till its minimum value at 50 % total life and then increases in the rest cycle course ; cycle strength coefficient and cycle strain hardening exponent both decrease during the total cycle course 结果表明: 6个基本疲劳特性参数在循环过程中都呈显出规律性变化。疲劳强度系数呈线性减小趋势;疲劳强度指数呈线性增大特征;疲劳延性系数是一个先增后降的过程;而疲劳延性指数随循环进行由初始减小到逐渐增大;循环强度系数和循环应变硬化指数在整个循环过程中都趋于减小。
Based on the damage evolution formation depicted by kachanov of brittle materials in unitary stress state , in this dissertation , the constitutive equation of nonlinear damage material is given , macroscopically , on the assumption that damage variable is exponential relation to strain , d = ( gy i k ) " , where g is the shear module , k is the damage module and the y is the effective strain , d is damage variable and n is hardening exponent 在kachanov描述的一维应力状态下的脆性材料的损伤演化模型的基础上,文中给出非线性损伤材料的本构方程,唯象地假设损伤变量与应变成幂次关系, d ~ * = ( g / k ) ~ n ,其中g为剪切模量, k为损伤模量,为有效应变因子, d为损伤变量, n为硬化指数。