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Press hardenable ultra high strength steel (UHSS) is commonly used for automotive components to meet crash requirements with minimal mass addition to the vehicle. Press hardenable steel (PHS) is capable of forming complex geometries with deep sections since the forming takes place at elevated temperatures up to 900 degrees Celsius (in the Austenitic phase). This forming process is known as hot-stamping. The most commonly used PHS grade is often referred to as PHS1500. After hot-stamping, it is typically required to have a yield strength greater than 950 MPa and a tensile strength greater than 1300 MPa. Most automotive design and material engineers are familiar with PHS, the hot-stamping process, and their capabilities. What is less known is the capability of 3rd Generation advanced high strength steels (AHSS) which are cold stamped, also capable of forming complex geometry, and are now in the process of, or have recently completed, qualification at most automotive manufacturers.

The ThyssenKrupp InCar Project is a comprehensive R&D development that gives automotive manufacturers modular solution kits for body, chassis, and powertrain applications. The solution kits developed within this project offer weight reduction, cost savings, or improved functionality. This paper will focus on the front longitudinal members of the body structure. The front longitudinal member is a key safety component responsible for absorbing energy in a frontal crash event. It must also have high local strength, stiffness, and fatigue resistance at the suspension attachment points. Within the InCar project, several different solutions for the front longitudinal members were developed, including stamped AHSS concepts, stamped AHSS tailored blank concepts, and tailored tube concepts using an innovative forming technology for closed section designs, called InForm T3 (Thyssen Tailored Tubes).

To improve the energy absorption capacity of front-end structures during a vehicle crash, a novel 12-sided cross-section was developed and tested. Computer-aided engineering (CAE) studies showed superior axial crash performance of the 12-sided component over more conventional cross-sections. When produced from advanced high strength steels (AHSS), the 12-sided cross-section offers opportunities for significant mass-savings for crash energy absorbing components such as front or rear rails and crush tips. In this study, physical crash tests and CAE modeling were conducted on tapered 12-sided samples fabricated from AHSS. The effects of crash trigger holes, different steel grades and bake hardening on crash behavior were examined. Crash sensitivity was also studied by using two different part fabrication methods and two crash test methods. The 12-sided components showed regular folding mode and excellent energy absorption capacity in axial crash tests.

The purpose of this paper is to show that certain steel skid plates can achieve up to a 50% weight reduction, with little or no increase in cost, by simply changing the shape and utilizing high strength steel. There are many factors that can influence the skid plate shape, including rail width, ground clearance, attachment points, drive shaft location, and the general shape of the object for which it is the skid plate's sole purpose to protect (fuel tank, transfer case, etc.). A skid plate is usually considered last from a design standpoint so that its design is dependent upon the environment which it is set in. For this reason, skid plates are generally heavy and flat to meet ground clearance requirements and have ribs inserted to increase stiffness. Sometimes design parameters require a skid plate to be heavy and flat. But more often, a stiffer lightweight design can be obtained.