GOALI/CRISP: Characterization of Geometric Variations for Design and Manufacturing of Aluminum Automotive Space-Frames

[9500006]王：该奖学金授予了学术联络与工业（GOALI）研究项目的资助机会，该项目将开发一种新的方法来减少铝汽车空间框架的几何变化。空间框架结构以“修补玩具”的方式由铝型材制成，它们保证重量轻，强度好，耐撞性好。小于0.5 mm的紧凑几何变化目标是为了确保这些结构在连接时具有良好的装配性，因此当用于制造门开口等特征时，它们可以达到其全部强度潜力。技术方法将使用坐标测量机（CMM）对结构形状进行测量，将这些数据参数化为偏差，形成所需结构形式的几何模型，并从该表示中确定工艺改进的需求，使用快速原型技术修改工具，并预测公差叠加。要解决的两种问题涉及到曲率：在一种情况下，名义上的直线挤压有弯曲，而在另一种情况下，弯曲挤压有偏离设计曲率或可能有多个弯曲。这项工作始于1994财年与美国铝业公司的GOALI/EFI奖，这种合作将继续进行该研究项目。这将使这些轻质结构框架构件的大批量生产成为可能，这些构件有助于提高汽车、飞机的安全性和燃油经济性，或者在强度和重量之间有重要权衡的地方。＊＊＊

9500006 Wang This award for a Grant Opportunity for Academic Liaison with Industry (GOALI) research project will develop a new methodology for reducing geometric variation in aluminum automotive space frames. The space frame structures are fabricated in a "Tinker Toy" manner from aluminum extrusions, and they promise light weight, very good strength and crash worthiness. Tight geometric variation targets of less than 0.5 mm are are to assure good fit-up when these structures are joined, so they reach their full strength potential when used to fabricate features like door openings. The technical approach will use measurements of the structural shapes made with a coordinate measuring machine (CMM), parameterizing this data as deviaitons form a geometric model of the desired structural form, and from this representation identify the needs for process improvement, modify tooling using rapid prototyping technology, and predicting tolerance stackup. Two of the types of problems that will be attacked that involve curvature: in one case nominally straight extrusions that have a bow, and in the other curved extrusions that have deviations from the design curvature or possibly multiple bends. This work began as a GOALI/EFI award with ALCOA in FY94, and this collaboration will continue with this research project. This will enable high volume manufacture of these light weight, structural frame members that contribute to safety and fuel economy in automobiles, aircraft, or where there are important strength to weight tradeoffs. ***