In order to minimize the computing cost the initial analysis was done in the plane normal to the welding direction as shown in figures 2-19 and 2-20. Thus, heat flow in the welding direction was neglected. The above simplification is accurate in situations where comparatively little heat flows from the arc in the welding direction. […]

Having selected a model for the heat source, the analyst has the option of assuming that the heat flows only in cross-sectional planes, only in the plane of the plate, only in a radial direction or is free to flow in all three dimensions, Figure 2-12. Such assumptions are analogous to those applied to the […]

Calculation experience with the ellipsoidal heat source model revealed that the temperature gradient in front of the heat source was not as steep as expected and the gentler gradient at the trailing edge of the molten pool was steeper than experimental measurementse. To overcome this limitation, two ellipsoidal sources were combined as shown in Figure […]

For welding situations, where the effective depth of penetration is small, the surface heat source model of Pavelic, Friedman and Krutz has been quite successful. However, for high power density sources such as the laser or electron beam, it ignores the digging action of the arc that transports heat well below the surface of the […]

In the ‘circular disc’ model proposed by Pavelic et al [40], the thermal flux has a Gaussian or normal distribution in the plane, Figure 2-6: q(r) = q(0)e~cr (24) where: q(r) = Surface flux at radius r(Wjm2) <7(0) = maximum flux at the center of the heat source (W/m2) С = distribution width coefficient (m~2) […]

The interaction of a heat source (arc, electron beam or laser) with a weld pool is a complex physical phenomenon that still cannot be modeled rigorously. It is known that the distribution of pressure and shear from the arc source, droplets from the electrode the effects of surface tension, buoyancy forces and molten metal viscosity […]

Theoretical Formulations The basic theory of heat flow that was developed by Fourier and applied to moving heat sources by Rosenthal [38] and Rykalin [37] in the late 1930s is still the most popular analytical method for calculating the thermal history of welds. As many researchers have shown, Rosenthal’s point or line heat source models […]

2.2.1 Computational Geometry In computer aided drafting, the computer stores the lines and symbols from the drawing, but does not understand them and cannot interpret them. With wire frame models that store vertices and edges, the computer has some understanding of the geometry and can rotate an object or at least its wire frame representation. […]

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 […]

Introduction and Synopsis Computer aided Design (CAD) and analysis and Computer Integrated Manufacturing (СІМ) are popular topics for research. Computer aided drafting and engineering analysis such as Finite Element Method (FEM) are well developed. Finger & Dixon [1 and 2] categorize research areas in their review of theory and methodology of mechanical design. They agree […]