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In automotive body manufacturing the dies for blanking/trimming/piercing are under most severe loading condition involving high contact stress at high impact loading and large number of cycles. With continuous increase in sheet metal strength, the trim die service life becomes a great concern for industries. In this study, competing trim die manufacturing routes were compared, including die raw materials produced by hot-working (wrought) vs. casting, edge-welding (as repaired condition) vs. bulk base metals (representing new tools), and the heat treatment method by induction hardening vs. furnace through-heating. CaldieTM, a Uddeholm trademarked grade was used as trim die material. The mechanical tests are performed using a WSU developed trimming simulator, with fatigue loading applied at cubic die specimen’s cutting edges through a tungsten carbide rod to accelerate the trim edge damage. The tests are periodically interrupted at specified cycles for measurement of die edge damage.

This paper deals with a virtual prototyping study, using VHDL-AMS language to model an automotive subsystem and to implement its control scheme. The automotive subsystem under study here is a control system for reference input wheel slip tracking. The control objective is to track a reference input wheel slip. A variable structure sliding mode controller is used to provide robust control of uncertain, often nonlinear, dynamical automotive systems. In this study, the main components of this control system, including the wheel dynamics, sensors, and control logic, are implemented in VHDL-ASM and the complete system is simulated in Simplorer®.

This paper introduces a new method to assist deep drawing of tailor-welded blanks with combined restraining force control and binder temperature control. The effect of variable flange temperature and blank holding force on the formability and weld-line displacement of aluminum tailor-welded blank was studied through Finite Element Analysis using LS-DYNA PC.

In this paper, an adaptive strain methodology is developed for experimental strain measurement in sheet metal panels. The principle involves etching uniform small square grids on the panel, and measuring strains adaptively from deformations of large squares comprising of many smaller grids. The methodology uses FEA predicted strains as input and accounts for the experimental noise. The methodology overcomes the inability of the existing practice to simultaneously measure both low and high strain features, and in addition, saves considerable measurement time. The methodology is simple and can be easily integrated with automated strain measurement systems. The algorithm is distinguished for plane strain or radial symmetric panels whose strains vary along 1D (one dimension) and for other panel types whose strains vary along 2D (x and y). Correspondingly, the adaptive methodology is demonstrated for a hemispherical punch stretched and a box drawn panel.

In recent years the use of tailor-welded blanks (TWB) has grown significantly, but there still exists serious concern on the poor formability in the stamping of TWB, which is commonly considered to relate to the uncertainty in the weld line movement. This paper proposes a drawbead design methodology to achieve weld line movement control. Based on the properties, geometries and frictions of base-metals constituting the TWB, the magnitudes and ratio of drawbead restraining force (DBRF) between the two sides of the base metal sheets across the weld line, which is the function of drawbead depth, can be determined for minimizing the weld-line movement and enhancing TWB formability. In the case of 2D strip drawing with TWB, lower restraining force should be used in the side of thicker base metal to reduce weld line movement.

Hot Metal Gas Forming is an innovative metal forming technique with the potential to leapfrog conventional metal forming techniques of structural steel components for automotive and aerospace industry. HMGF is an outgrowth of superplastic forming (SPF) and hot blow forming (HBF) techniques that the aerospace industry developed to form aluminum and titanium structures. The goal of this program is to develop the HMGF process and prove its production readiness for wide spread use in the Automotive and Aerospace industries by proving process robustness. An early process concept is shown below.

Adhesive joining is a common autobody subassembly technique especially for outer panels, where visible spot welding is objectionable. To accommodate mass production with the use of certain adhesives very high thermal gradient usually exists, which may result in panel dimensional distortion and variation. The temperature distribution over location and over time are monitored, and its impact to panel dimension is investigated. Experimental results on the effect of the distance between panel and induction coil on the panel temperature is obtained. The thermal induced shape distortion is simulated with a simplified FEA model. The approach to improvement of the induction curing process is discussed.