摘要
以一种新的、更符合实际的力学计算模型-移动荷载下粘弹性地基板系统来研究场道的无损检测理论.基于线性系统的叠加原理和坐标变换,建立了求解移动荷载下粘弹性地基板的动力响应广义积分公式,把运动荷载问题转化为获取位移脉冲响应函数.然后在柱坐标中利用拉普拉斯和汉克尔变换求解板在瞬时点源荷载作用下的解,再结合广义积分得到道面板在移动荷载作用下的弯沉解析解.以此为基础,采用最小二乘方准则,通过实测弯沉与理论弯沉相拟合,快速识别出E.通过实例计算,表明本文结果正确,基本理论和方法可应用于无损检测技术中来获取地基模量E.
The forming process of unstable onion ring and impact of process parameters on the forming of onion ring during friction stir welding are analyzed. The melt metal, specially that in the opposite direction from the rotation of weld pin, flows into hole and then destoryed the original metal flow field while weld pin did not move. Consequently, a complicated whirlpool flow field , which appears the disparity vertically is produced. Finally, the onion ring like appearance is formed. The experiment indicates： The size of the tool and the welding speed are main factors to influence the onion ring pattern.
出处
《西安工业学院学报》
2005年第2期164-168,共5页
Journal of Xi'an Institute of Technology
关键词
粘弹性地基
无损检测
积分变换
参数识别
friction stir welding
onion ring
unstable state flow field
welding speed
