Simulation and Reliability Analysis of Laser-Welded Blanks after Metal Surface Finishing Process

Currently there is a huge competition amongst the OEMs and manufacturers in the auto industry to reduce the weight of the car. A few design modifications or use of different size and grades of materials solves this problem greatly. This paper focuses upon the metal finishing process of Laser Welded Blanks (LWB) with simulation and reliability as well as new process development. These blanks are of same gauge-same gauge or different gauge-different gauge materials. The main aim of this process was to remove the visible portion of the weld on the blank, so that it can be used as a body-outer. A new process was developed using expert knowledge and automated machinery tools. A simulation model was developed to compare with the actual developed method and to detect the bottlenecks and optimize the process. Reliability was a major concern during laser-welded blank operations. The paper addresses prediction of the amount of material removed based on the failed parts and visibility of the weld. This approach could provide competitiveness in the weight of the car which is directly related to fuel efficient and long term survival. DOI: 10.4018/ijmmme.2012100101 2 International Journal of Manufacturing, Materials, and Mechanical Engineering, 2(4), 1-11, October-December 2012 Copyright © 2012, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. components but, ‘Body in White’ or ‘BIW’ refers to the stage in automobile manufacturing in which the car body sheet metal (including doors, hoods, and deck lids) has been assembled or designed but before the components (chassis, motor) and trim (windshields, seats, upholstery, electronics, etc.) have been added. The largest components of this BIW consist of ‘Body Inner’ and ‘Body Outer.’ There is one ‘Body Inner’ and one ‘Body Outer’ on each side of the car. It’s a one single component of sheet metal, starting from fender till the headlight-front bumper joint connection. As each section is a cut out of a large role of sheet metal, to reduce the scrap while manufacturing, OEMs has to come up with an optimum design. When we say optimum, it includes its strength, rigidity, elasticity, etc. which engineers needs to handle carefully while designing. Figure 1 shows a body-in-white (BIW) of a car. In the literature, several studies are conducted for reducing weight. Salchow (2005) illustrated laser welded blanks for reducing weight and cost. In another article, Wilson (2003) mentioned that the steel industry offers solutions for an auto industry bent on trimming cost and weight using similar techniques. Anon (2002) used some laser welded tubular blanks for lighter car components. There are many similar studies could be found in the published research. Múnera et al. (2009) presented innovative press hardened steel based laser welded blanks solutions for weight reduction and safety improvement. In term of reliability of the methodology, Chien et al. (2003) showed failure prediction of aluminum laser-welded blanks. Dry et al. (2001) provided methodology of assessing influence of weld properties on formability of laser welded tailored blanks. Qiu et al. (2007) studies numerical simulation on laser tailor welded blanks stamping. In another study, Cheng et al. (2005) investigated weldability and forming behavior of alumni tailor-welded blanks. Xia et al. (2008) studies failure analysis on laser welds for dual phase steel. Finite-element simulation for stamping and application to the forming of laser-welded blanks illustrated overall improvement (Iwata et al., 1995). There are many benefits of using tailor-welded blanks in car design (Rooks, 2001; Assunção et al., 2009). Laser weld blanks methodology could provide needed fuel efficient car with weight reduction. Laser welding is a technique which bonds two same gauge-same gauge or different gaugedifferent gauge materials. It also allows us to weld two portions of different metals and also of different grades. OEMs use these different combinations for the laser welding process for different body components. So laser welding helps in reducing scrap and at the same time it gives us freedom to design for the required condition. This laser welding process is used in many industries today where the weight savings is a must. In auto industry, this laser welding process is used to manufacture many body components including Body Inner. But the major drawback of this process is that the weld line is Figure 1. Body in white 9 more pages are available in the full version of this document, which may be purchased using the "Add to Cart" button on the product's webpage: www.igi-global.com/article/simulation-reliability-analysislaser-welded/73924?camid=4v1 This title is available in InfoSci-Journals, InfoSci-Journal Disciplines Engineering, Natural, and Physical Science. Recommend this product to your librarian: www.igi-global.com/e-resources/libraryrecommendation/?id=2