Integrated design of landing gear clevis joints

SPP加拿大飞机公司(SPPCA)是住友精密产品公司(SPP)的全资子公司，该公司于2012年4月在安大略省密西索加开设了起落架部门。SPPCA从事商业起落架和系统的工程、设计、采购、组装、销售和营销以及客户支持。目前，SPPCA正专注于扩大其能力，并有强烈的意愿增加其研发活动。在起落架总重量中，大约80%由主要的结构接头组成，如夹头接头。起落架夹头接头通常由许多部件组成，包括耳片、插座、衬套和销。连接设计涉及到基于接触力学确定这些部件的尺寸。当前的顺序运动类型设计过程耗费大量时间和成本，因为在确定运动类型大小之前必须迭代多次。这一设计缺陷影响了公司的竞争力。因此，该公司已与瑞尔森接洽，研究一种可以将所有接触问题结合在一起并同时解决它们的集成设计方法。在这个项目中，潜在的设计问题被描述为设计优化问题。目标函数是使关节的强度与重量之比最大化。设计变量包括联接几何图形、零部件尺寸和材料。所需的分析被视为包括静态接触应力、动态接触应力(与疲劳有关)和摩擦/滑动运动引起的剪应力的约束。常用的搜索方法，如通用算法，将被应用来解决这个问题。程序验证将对照商业包实现的相同设计的结果进行。随着具有成本效益的设计工具的开发，可以缩短设计周转时间，公司在合同方面将变得更具竞争力

SPP Canada Aircraft Inc. (SPPCA) is a wholly owned subsidiary of Sumitomo Precision Products (SPP) that has opened up a landing gear division in Mississauga, Ontario in April 2012. SPPCA is involved in engineering, design, procurement, assembly, sales & marketing and customer support for commercial landing gears and systems. Currently, SPPCA is focused on expanding its capabilities and has a strong desire to increase its R&D activity. Of the total landing gear weight, approximately 80% is comprised of major structural joints, such as clevis joints. A landing gear clevis joint typically consists of a number components including lug, socket, bushing and pin. The joint design involves the determination of the dimensions of these components based on contact mechanics. The current sequential joint design procedure is time and cost intensive as it must be iterated a number of times before a joint can be sized. This design drawback has affected the company's competitiveness. Therefore, the company has approached Ryerson to investigate an integrated design method that can combine all contact problems together and solve them simultaneously. In this project, the underlying design problem is formulated as a design optimization problem. The objective function is to maximize the strength to weight ratio of the joint. Design variables include joint geometry, component sizes and materials. Required analyses are treated as constraints covering static contact stress, dynamic contact stress (related to fatigue), and shear stress due to friction/slip motion. Commonly used search methods, such as Generic Algorithms, will be applied to solve this problem. Program validation will be carried out against the results of the same design achieved by a commercial package. With the development of a cost-effective design tool that can reduce in design turnaround time, the company will become more competitive for contract