动态碎裂过程中的最快速卸载现象

发布时间：2018-05-31 06:39

  本文选题：碎裂 + 裂纹阵列　； 参考：《中国科学:技术科学》2016年04期

【摘要】：固体在高应变率加载作用下常常断裂成多个碎片.Grady针对韧性碎裂和脆性碎裂提出了一个同样形式的碎片尺度预测公式,对韧性碎裂结果预测较好,而对脆性碎裂结果的预测相对较差.是否存在一种物理机制可以同时阐述韧性碎裂和脆性碎裂过程呢?本文借鉴Grady解决绝热剪切问题时提出的最小集中化时间的思想,认为固体的动态碎裂过程中存在着最快速卸载现象.对韧性碎裂过程和脆性碎裂过程从理论和数值计算上进行分析,发现最快速卸载理论得到的平均碎片尺度和目前文献报道结果均吻合较好.
[Abstract]:Under the action of high strain rate loading, the solid often breaks into several fragments. Grady puts forward a prediction formula for ductile and brittle fragmentation in the same form, which is a good predictor of the results of ductile fragmentation. But the prediction of brittle fracture results is relatively poor. Is there a physical mechanism that can describe both ductile and brittle fragmentation processes? Based on the idea of minimum centralization time proposed by Grady for solving adiabatic shear problems, it is considered that there exists the fastest unloading phenomenon in the process of dynamic fragmentation of solids. Based on the theoretical and numerical analysis of ductile and brittle fragmentation processes, it is found that the average fragment size obtained from the most rapid unloading theory is in good agreement with the reported results in the literature.
【作者单位】： 宁波大学冲击与安全工程教育部重点实验室;香港科技大学机械与航空航天工程系;
【基金】：国家自然科学基金(批准号:11402130,11272163,11390361) 宁波大学王宽诚幸福基金资助项目
【分类号】：O346.1
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本文编号：1958682