感应加热板材成形的有限元分析及工艺规划

通过感应加热实现板材的热弯成形,具有精准控制、安全便捷等特点。本研究采用新型便携式感应加热设备,对8mm船板钢进行热弯成形试验;并基于热-弹-塑性及弹性有限元计算,预测感应加热面外弯曲变形,与测量数据基本吻合。同时,考虑试验成本高昂,通过大通量的有限性计算,建立感应加热参数与板材弯曲的数据库;并通过回归分析,拟合出感应线圈移动速度与板材弯曲角度间的数学关系。当板材弯曲曲率相同时,通过线加热位置的迭代二分法,可线性逼近板材的目标弯曲形状,进而快速规划加工工艺,并进行了验证。     

集装箱船货舱成型精度控制

从导轨架制作精度控制、导轨架安装精度控制、横舱壁分段总组精度控制和横舱壁总段合龙精度控制等关键环节进行集装箱船货舱成型精度控制。研发应用高精度检测工装,获取集装箱船货舱成型精度数据,实现高效精准完成吊箱试验的目标。     

水冷PEMFC热管理系统建模和控制

为了维持质子交换膜燃料电池（Proton Exchange Membrane Fuel Cell, PEMFC）工作在合理的温度区间,文章首先建立了PEMFC热管理系统的电堆温度模型和电堆冷却回路模型,然后建立了PEMFC本体模型,并进行了本体模型的验证,采用基于Bang-Bang控制的热管理控制策略,并进行了离线仿真和快速控制原型试验。结果表明：在不同的电流负载变化的情况下,电堆能够很好地保持在目标温度（70±1）℃,散热器冷却水温度保持在目标温度（70±2）℃,达到了预期的控制效果。     

Finite Element Optimization of Vee-ring Factor in Fine-blanking Process

The vee-ring is one of the most characteristic features of the fine-blanking process which is derived from the conventional blanking. With the vee-ring, a counter plate and some other working parameters, a component with a precise geometry and smoothly blanked surface can be produced without any major secondary operations. However, these working parameters are always empirically determined or determined by trial-and-error method, which is time-consuming and expensive. In this study, a numerical simulation method was used to analyze the effect of vee-ring factors on product quality, such as distance between vee-ring and punch, vee-ring height and blank holder force, so as to obtain as high clean cut ratio as possible. During the simulation, the model was assumed as axisymmetric one and the workpiece was considered as rigid plastic material, meanwhile the tools were defined as rigid bodies so as to shorten the computational time. A damage model taking into account the influence of hydrostatic stress was used to simulate material fracture in fine-blanking. The result obtained from the simulation indicated that with the help of vee-ring, the metal material near the shear band does not flow with the punch penetration and high compressive stress in the shear band is generated. Consequently, higher clean cut ratio can be obtained with a vee-ring model than the one obtained with a plane blank holder model. Furthermore, the longer the distance between vee-ring and punch is, the higher the height of roll-over becomes.     

沥青混凝土温度应力试验研究

沥青混凝土路面的低温开裂问题一直是道路工程界人士研究的一个热点问题，美国公路发展战略（SHRP）综合分析了以前各种用于分析、研究沥青混凝土温度开裂问题的试验方法后，认为只有约束试件温度应力试验（TSRST）能正确的模拟路面的现场情况，提出采用约束试件温度应力试验（TSRST）来研究沥青路面的低温开裂问题，还提出了相应的试验标准，对试验数据的分析、处理等也提出了一整套方法，笔者在采用TSRST进行大量试验的基础上，指出SHRP提出的温度应力典型曲线的不足，提出了完整的温度应力曲线规律，最后探讨了初始温度降温速率等对温度应力的影响。