曲面薄板注塑成型翘曲数值模拟及优化

利用Moldflow的MPI/Warp分析模块对曲面薄板塑件注射成型冷却过程进行数值模拟,预测其成型后的翘曲变形。通过正交试验法对影响塑件翘曲变形的工艺参数进行优化,确定影响该塑件翘曲变形的主要因素为材料收缩性能,其次为模具温度、注射保压冷却时间和熔体温度,并给出工艺优化方案。所获得结果可以用于指导和优化实际生产工艺。

异形曲面混凝土薄板施工技术探究

文章针对芜湖赭山印象工程结构特点,介绍了异形曲面混凝土薄板的轴线标高定位、支模工艺、混凝土浇筑、质量控制等关键环节的操作方法和施工难点。

大型曲面薄壁件多点柔性工装装夹布局优化

采用Python脚本语言对ABAQUS的前处理模块进行二次开发,将铣削力依次加载到铣削区域各点,获得由让刀产生的轮廓度误差与装夹布局关系数据;根据多元非线性回归理论建立以支撑单元布局为设计参数的大型曲面薄板件让刀误差数学模型,并采用全局寻优能力较强的遗传算法进行布局优化。结果表明:优化后的支撑单元布局合理,系统资源利用率最佳,与均匀布局相比轮廓度误差降低了39.1%,满足了飞行器薄板件的高速高精加工需求。

液压成型幕墙曲面板的受力分析和实验研究

本文阐述液压成型幕墙曲面板的简化模型 ,在弹性范围内分析 ,幕墙曲面板的受力和支承系统 ,可以简化为四角铰支在集中载荷作用下的平板。用有限单元法计算雏形平板的应力和位移。文中介绍冷挤压雏形幕墙曲面板的实验和液压加载系统。最后给出幕墙曲面板在幕墙工程中应用的实例。

Propagation of flexural waves in phononic crystal thin plates with linear defects

The band structures of flexural waves in a phononic crystal thin plate with straight, bending or branching linear defects are theoretically investigated using the supercell technique based on the improved plane wave expansion method. We show the existence of an absolute band gap of the perfect phononic crystal and linear defect modes inside the gap caused by localization of flexural waves at or near the defects. The displacement distributions show that flexural waves can transmit well along the straight linear defect created by removing one row of cylinders from the perfect phononic crystals for almost all the frequencies falling in the band gap, which indicates that this structure can act as a high efficiency waveguide. However, for bending or branching linear defects, there exist both guided and localized modes, and therefore the phononic crystals could be served as waveguides or filters.