摘要：本文旨在研究石墨烯片增强功能梯度多孔梁材料不确定性对在热环境下的过屈曲行为的影响.通过采用随机有限元方法,已经完成了全面的确定性和随机性研究.考虑了温度依赖性(TD)和温度无关性(TID)的材料特性.使用Halpin-Tsai微力学模型估计了杨氏模量等均质化有效材料性质,通过Voigt混合法则估计了密度和热膨胀系数.假设均质化的材料特性沿厚度方向以功能渐变的方式变化.所开发的公式基于高阶剪切变形理论,结合冯-卡门型几何非线性进行过屈曲分析.开发C^(0)有限元模型求解非线性控制方程组,使用直接迭代过程进行数值求解.所开发方法的收敛和验证研究也通过独立的蒙特卡罗模拟进行,以确保方法的准确性.分别讨论了材料设计参数如孔隙率含量、纳米填料量和材料特性(即杨氏模量、金属基体密度和纳米填料)的低变异性(随机性)等材料不确定性对FGGPLRC多孔梁热机械过屈曲行为的影响.结果表明,材料性能的不确定性会显著影响FG-GPLRC多孔梁的过屈曲响应.

摘要：Standard costing is used as a control for product costing. But with life cycle becoming shorter, costing should be done at the design and development stage of a product. This is achieved through target *** implementation of target costing and target pricing is done with the ultimate purpose of cost reduction, cost understanding, continuous improvement, competitiveness, early purchasing and supplier involvement, and improved design and accountability by manufacturers. The study explores the participation of the purchasing and supply chain management＇s role in target costing and target pricing process. Supply management plays an active role in monitoring the ongoing cost and performance of suppliers during the early stages of product development. Implementation of target costing and target pricing in various organizations are also explored. Leading Japanese manufacturers have used target costing and target pricing systems to their advantage and the paper also examines the adaptation of the Western companies to these proactive cost management techniques to improve their product development processes.