摘要
为了研究不同温度及应变速率下刨链的强度和寿命特征,以变形条件对圆环链临界损伤因子的影响为主要研究目标,确立物理试验与数值模拟仿真相互佐证寻求临界损伤因子的基本思路,完成不同温度和应变速率条件下多组试样的热物理模拟拉伸试验.发现最大损伤值总是出现在圆环链的肩部,损伤软化现象对应变速率较为敏感,临界损伤因子不是一个常数,而是在0.15～0.54范围内;对刨链的接触应力点进行统计,采用改进雨流法、线性Miner疲劳累计损伤方法,建立刨链在工作时的应力变化幅值及行程累积损伤模型,并计算出刨链的破碎行程个数及时间.研究结果表明,采用宏细观角度研究刨链的损伤机理可行,该方法对于反映刨链的实际使用工况和预测刨链的使用寿命具有重要的意义.
To analyze the influence of deformation conditions on the critical damage factor of high strength ring chain, a basic research approach combine physical experiments with numerical simu- lation to search the critical damage factor was established. Several series of billet samples had been compressed on heat physical simulation machine under different deformation temperatures and strain rates, the true stress-strain data collected recorded the performance of simulations. Simulation results show that the maximum damage value appears on the outer edge of round-link chain, and damage softening behavior is more sensitive to strain rate. A concept of damage sensi- tive rate was brought in and its values were calculated. The intersection of line fitted and horizon- tal axis were obtained as the fracture step and its relative maximum damage value was a critical damage factor. The critical damage value distribution recorded shows that it is not a constan~ but changes in a range of 0.15-0. 54 , and it is more sensitive to strain rate than temperature. We es- tablish the variation of stresses amplitude of the plane chain during working and travel cumulative damage model by using improved rain flow and linear Miner fatigue cumulative damage, then calculates the plane chain broken itinerary number and time. The results show that the macro and micro theory is feasible to study the damage mechanism of the plow chain, and it has important significance to reflect the practical service condition and to predict the working life of the plow chain.
出处
《工程设计学报》
CSCD
北大核心
2013年第3期189-194,共6页
Chinese Journal of Engineering Design
基金
国家高技术研究发展计划(863计划)资助项目(2013AA06A412)
国家科技支撑计划资助项目(2013BAH12F01)
工业装备结构分析国家重点实验室开放基金资助项目(GZ0818)
辽宁省教育厅科研项目计划资助项目(L2011050)
北京科技新星支持计划项目(2012)
关键词
热物理模拟
临界损伤因子
改进雨流法
强度
圆环链
heat physical simulation
critical damage value
improvement of rain-flow
strength
ring chain
