DOE OSTI2013
Many US manufacturing companies have moved fabrication and production facilities off shore because of cheaper labor costs. A key aspect in bringing these jobs back to the US is the use of technology to render US-made fabrications more efficient overall with higher quality. A new initiative of the current administration has the goal of enhancing competitiveness to retain manufacturing jobs in the US. One significant competitive advantage that has emerged in the US over the last two decades is the use of virtual design for fabrication of large structures in the light and heavy materials industries. Industries that have used virtual design and analysis tools have reduced material parts size, developed environmentally-friendly fabrication processes, improved product quality and performance, and reduced manufacturing costs. Indeed, Caterpillar Inc. (CAT), one of the partners in this effort, continues to have a large fabrication presence in the US because of the use of weld fabrication modeling to optimize fabrications by controlling weld residual stresses and distortions and improving fatigue, corrosion, and fracture performance. This report describes Engineering Mechanics Corporation of Columbus (Emc2's) DOE SBIR Phase I results which extended an existing, state-of-the-art software code, VFT, currently used to design and model large welded structures prior to fabrication - to a broader range of products with widespread applications for small and medium-sized enterprises (SMEs). VFT helps control distortion, can minimize and/or control residual stresses, control welding microstructure, and pre-determine welding parameters such as weld-sequencing, pre-bending, thermal-tensioning, etc. VFT uses material properties, consumable properties, etc. as inputs. Through VFT, manufacturing companies can avoid costly design changes after fabrication. This leads to the concept of joint design/fabrication where these important disciplines are intimately linked to minimize fabrication costs. VFT currently is tied to a commercial solver which makes it prohibitively expensive for use by SMEs, as there is a significant licensing cost for the solver - over and above for the relatively minimal cost for VFT. Emc2 developed this software code over a number of years in close cooperation with CAT (Peoria, IL), who currently uses this code exclusively for worldwide fabrication, product design and development activities. The use of VFT has allowed CAT to move directly from design to product fabrication and helped eliminate (to a large extent) new product prototyping and subsequent testing. Additionally, CAT has been able to eliminate/reduce costly one-of-a-kind appliances used to reduce distortion effects due to fabrication. In this context, SMEs can realize the same kind of improved product quality and reduced cost through adoption of the adapted version of VFT for design and subsequent manufacture of new products. Emc2's DOE SBIR Phase I effort successfully adapted VFT so that SMEs have access to this sophisticated and proven methodology that is quick, accurate and cost effective and available on-demand to address weld-simulation and fabrication problems prior to manufacture. The open source code, WARP3D, a high performance finite element code mainly used in fracture and damage assessment of structures, was modified so that computational weld problems can be solved efficiently on multiple processors and threads with VFT. The thermal solver for VFT, based on a series of closed form solution approximations, was enhanced for solution on multiple processors greatly increasing overall speed. In addition, the graphical user interface (GUI) has been tailored to integrate these solutions with WARP3D. The GUI is used to define all the weld pass descriptions, number of passes, material properties, consumable properties, weld speed, etc. for the structure to be modeled. The GUI was improved to make it user-friendly for engineers that are not experts in finite element modeling. Finally, a plan for porting VFT onto the Ohio Supercomputer Center (OSC) through its hosted Manufacturing and Polymer Portal has been developed. This access route will permit SMEs to perform weld modeling to improve their competitiveness at a reasonable cost. All of these improvements are detailed in this repo
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗