Testing Methodology to Characterize GMA Welds for use in FEA Simulation******

汽车生产商希望在气体金属弧焊（GMAW）车架应用中增加先进高强度钢（AHSS）的使用。这将使零件由比目前使用的更薄的钢材制成，减少零件重量，提高车辆燃油经济性，同时保持或提高车辆安全性。然而，当AHSS是GMAW时，由于其复杂的化学成分和微观结构，许多AHSS表现出不均匀的性能，表现出局部的高硬度和低硬度。这种硬度变化导致强度测试结果的变化，因此数据不能用于零件设计所需的数值模拟模型。****该项目将开发一种测试方法，以表征搭接剪切接头的拉伸焊接强度，这可能用作设计汽车零部件所需模型的输入。该方法将被设计成可以使用工业上可用的标准测试方法来实施。通过增加被测接头的对称性来改进测试方法，然后通过将测试结果与理想情况下的对接接头结构中的焊缝进行比较，以及使用仪器硬度测试数据计算的HAZ各个区域的局部应力应变数据进行验证。****实施该项目的成果是将重型（bbb2.0 mm） AHSS集成到框架应用中的第一步。在车架应用中增加AHSS的使用将允许更薄的材料用于汽车设计，减少车辆重量并减少对环境的影响。这将使加拿大受益：减少新车的环境足迹，为加拿大公司（如Martinrea）提供制造技术，以生产新等级的钢材，并为加拿大钢铁制造商（如Stelco和ArcelorMittal Dofasco）提供销售其新AHSS等级的市场。

Automotive producers would like to increase use of advanced high strength steel (AHSS) in gas metal arc welded (GMAW) frame applications. This would allow parts to be made from thinner gauges of steel than are currently used, reducing part weight, and improving vehicle fuel economy, while maintaining or increasing vehicle safety. However, when AHSS are GMAW, many AHSS exhibit heterogeneous properties exhibiting local areas of high and low hardness due to their complex chemical composition and microstructures. This hardness variation leads to variations in results during strength testing so that the data cannot be used to inform numerical simulation models needed for part design.****This project will develop a testing methodology to characterize the tensile weld strength of lap shear joints, which may be used as input for the models needed to design automotive parts. The method will be designed so that it may be implemented using standard testing methods available to industry. The test method will be improved by increasing the symmetry of the tested joint, and then validated by comparing test results to welds made in a butt joint configuration, which is the ideal case, and local stress-strain data from various areas of the HAZ, calculated using instrumented hardness test data.****Implementing the results of this project is the first step to integrating heavy (>2 mm) AHSS into frame applications. Increasing use of AHSS in frame application will allow thinner materials to be used for automotive designs decreasing vehicle weight and reducing their environmental impact. This will benefit Canada by: reducing the environmental footprint of new vehicles, providing manufacturing know-how to Canadian companies, such as Martinrea, to manufacture new grades of steel, and provide a market for Canadian steelmakers such as Stelco and ArcelorMittal Dofasco to sell their new AHSS grades.