Simplified Modeling and Mathematical Analysis in Cardiac Electric Field Propagation for Human and Animals

The different characteristics of cardiac electric field(CEF)radiation in humans and other animals are presented in this paper.Physical modeling and mathematical analysis are developed to comprehensively unveil the properties of CEF,based on typical heartbeat waveforms.Our numerical simulation results demonstrate that the frequency bandwidths and the cycle durations of CEF are different for healthy humans versus humans on the verge of death and for humans versus other animals.The results indicate that the present study may extensively contribute towards recognizing human beings or other animal targets quickly and accurately with CEF in dangerous situations or in other applications.

基于螺栓滑移的K型节点受力性能分析

文章建立了与K型节点试验相对应的有限元模型,该模型考虑了材料非线性、几何非线性、状态非线性等因素的影响,模拟试验工况的加载方式。在模型得到验证的基础上,建立80组K型节点的有限元模型,通过对节点弯矩-转角曲线的研究,对该类节点的受力性能进行参数化分析。主要研究了主角钢规格、螺栓个数、螺栓间距、施工扭矩、螺栓强度等因素对于节点转动滑移的初始刚度、滑动荷载、滑移转角、极限转角、极限弯矩等关键性参数的影响。在此基础上,提出了基于螺栓滑移的K型节点弯矩-转角曲线计算方法。通过较为全面的参数分析得知,螺栓个数对节点初始转动刚度的影响最大,可用来较大地调整节点初始转动刚度;其他因素影响相对较弱,按影响能力的大小依次为螺栓间距、螺栓直径、肢厚、节点板厚和肢宽。