COMPUTATIONAL WELDING MECHANICS

MANUFACTURING

Figure 2-1: Tools for evaluation of manufacturing effects between functional evaluation and planning of manufacturing (vertical) also between concept and details (horizontal), from [3 and 4].

In Figure 2-1, the upper part presents the traditional tools for functional evaluation and the lower part show the systems for computer aided design and finite element programs. Design engineers will use these tools, especially to improve the product and its functionality as much as possible. Weld simulation belongs to the middle part which includes tools for evaluation of manufacturing effects. This covers the most negative effects of manufacturing, on the properties in different phases of the process leading to defects in material state, form accuracy, measurement tolerance, strength, hardness and other quality features. The development of tools dedicated to supporting the evaluation of manufacturing effects has lagged due to the complexity of simulation processes. In Figure 2-1 the lower part demonstrates the current tools for planning of manufacturing, and above it, systems for programming robots and controlling material flow. Manufacturing engineers will use these tools especially to improve the production sequence and flow of material in the factory increasing the revenue of the manufactured product. Development steps from concept to detail in design and in manufacturing are shown in boxes. These steps must be run concurrently (simultaneous engineering), for which computing tools are inevitable requirements. Effort will be made in the entire process range, from raw material to the finished product, to include computers and simulations.

The calculation of weld simulation could not ignore computing tools in the future for innovative development of weld processes, weld design and their materials. Chihoski’s [5] recommendation still says it best: “A changed set of conditions often changes the weld quality too subtly to be seen, except in large quantities, and there are too many possible changes to try. Hit or miss changes in the perfect lab (the production shop) are often not permitted. It would seem then to be of great use to the welding industry to develop and evolve computer programs that rigorously portray the stress and strain arrangements for different weld conditions. This route may be the only path from the current state of technology to the ideal in scientific promise, where a manufacturer who chooses an alloy and thickness and weld conditions can compute the value of each of the other weld conditions that minimize production problems”.