Joint configurations

Templates for each of the joint configurations are stored within the system. The operator selects one of the templates, and is provided with a visual representation, as shown in Figure 3, on which he can alter the Joint dimensions and weld geometry to match those of the item to be examined any ae-cess restrictions can also be defined. Using information from a database of available probes, along with the examination level required, ProcGen then calculates the set of scans required (see Figure 4). 

Assuming that after their previous swap the two walks were sufficiently long to be in the asymptotic regime, this means that transient behavior has elapsed and the system has relaxed to equilibrium for the respective parameters. Then, the joint configurational probability density just before the current swap is simply... 

A typical freely jointed chain will therefore be quite compact since the root-mean-square value of its end-to-end length, J(ft2) = f N b, will be small compared with its length if it were stretched out (i.e., Nb, when N is large). Figure 10.9 shows a simulated molecule of polyethylene, (-CH2-CH2-)/v, which approximates a freely jointed configuration. 

Fig. 2. Representative brazing joint configurations. (Lucas-Milhaupt, Inc., A Hands Harman Company)...

Adhesive joint designers will take maximum advantage of this second effect by designing the joint configuration for protection or by specifying a protective coating and/or sealant around the exposed edges of the adhesive. 

Specific substrates are described under each classification. Of course, adhesive applications are not limited to joints having only one type of substrate. Metal-to-plastic, aluminum-to-steel, metal-to-wood, glass-to-metal, and an infinite variety of other joint configurations are all possible. In these applications the nature of each substrate needs to be understood and considered in the overall selection of an adhesive formulation and bonding process. 

Figure 10.3. Some preferred joint configurations for brazed metal components.

Figure 1. The typical thermal cycle for diffusion bonding of AI2O3 ceramic to Ni-superalloy (a) and the joint microstructure with the optimised joint configuration using interlayers (b).

Considering the fact that the calculations strictly apply to a cylindrical joint configuration and monolithic ceramics rather than anisotropic materials such as composites, and the fact that chemical interactions and solute segregation will irrevocably and unpredictably modulate the joint properties, the calculated strain energy values are probably reasonable. 

Fig. 1.3 Joint configurations for friction stir welding, (a) Square butt, (b) Edge butt, (c) T-butt joint, (d) Lap joint, (e) Multiple lap joint. (f) T-lap joint, (g) Fillet joint. Source Ref 14...

Alloy 201. A 3.2 mm (0.125 in.) thick alloy 201 sheet was welded in a butt joint configuration using a tool with a 16 mm (0.63 in.) diameter shoulder. The weld was a partial penetration weld, to avoid complications associated with getting the pin close to the backing plate. Yield and tensile strengths of the weld metal were 193 and448 MPa (28 and 65 ksi), respectively, compared with 103 and 406 MPa (15 and 60 ksi) for the base material. Elongation was 34% for the transverse specimen, compared to 50% for the base material. Very little tool wear was observed in this weld. 

Joint Type. There are several basic joint configurations where FSW can be applied. These different joint configurations can affect the requirements of the FSW machine. The following lists the joint configurations and their effects on the machine requirements. 

For complex joint configurations try both simplifications or consult TWI. 

As mentioned, large commercial aircraft contain about three million fasteners, and so a multitude of bolted joint configurations exist. However, despite this diversity, there is a basic commonality in the stresses set up by the fastener or bolt load at a particular bolthole, and the effect of other loaded bolt-holes on this stress distribution [1], This allows simplified coupon tests to be used in establishing design criteria and data for these various joint configurations. The intent is to then combine a suitable number of test/ model results to represent the actual situation. 

For this study, two different joint configurations were considered. The first was a C1 C1 C1 joint with neat-fit clearances at each bolt-hole, and the other (C4 C1 C1) had a 240 pm clearance at bolt-hole No. 1, as shown in Table 11.4. 

Three tests to failure on the C1 C1 C1 joint configuration were carried out in [41]. The study found that one joint failed in net-tension at hole 1 in the lower laminate at a joint load of 80 kN, while another failed by net-tension at hole 3 in the top laminate at 84 kN. The third joint tested failed by bolt failure at 76 kN. It should be noted that bearing damage was evident at holes where bolt failure occurred. However, as this damage mode is non-catastrophic, high loads are transferred through the bolt until... 

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