Joint simulation test

Representation of Wear Scar in Leeds Knee Joint. (Simulator Test). 

Attention is drawn to the value of joint simulation testing as a means of confirming selected procedures this is discussed at the end of the chapter. 

Joint simulation tests are of particular value in confirming weldi procedures for these steels where there may be insufficient data ( behaviour and critical hydrogen levels. 

An example illustrates a very simple case where a joint simulation test can create a high degree of assurance of success for a procedure which, incidentally, is less stringent than that indicated by relevant sections of this book. It must be emphasised that this is an example only and does not constitute a suggestion for general relaxation of recommendations. 

Table 2.5 Details of welds to be made in joint simulation test illustrated in Fig, 2.8...

Joint simulation test geometry the three stiffeners are numbered in order of welding. 

However, the fabricator is a cautious man and, although he is confident that he will need no preheat, he designs his joint simulation test so that he can include test welds made with some preheat. He therefore makes the fabricated beam 2 m long, so that he can include three stiffeners staggered on either side of the beam as shown in Fig. 2.9. He also selects the plates which have the maximum CE of... 

Diagram for selecting minimum preheat, interpass and postheat temperatures for alloy and lean alloy steels giving fully hardened HAZs. Note relaxation of preheat temperatures may be possible with low hydrogen processes and thin sections, particularly at low C contents. Confirmation should be obtained by joint simulation tests. For class of steel refer to Table 4.3... 

Note Relaxation of preheat temperatures may be possible with low hydrogen processes and thin sections, particularly at low C contents. Confirmation should be sought by joint simulation tests. 

At low hardness values (below about 450 HV), low preheat and interpass temperatures are predicted and postweld heating may not be necessary. A further reduction of temperature may be possible if very low hydrogen processes can be used, but this should be confirmed by joint simulation tests. For example, in maraging steels graded M and having a maximum carbon content of 0.02%, Fig. 

Jani S., and M. Scott. 2003. Wear debris generation in joint simulator testing of crosslinked UHMWPE. In Highly crosslinked and thermally treated ultra-high molecular weight polyethylene for joint replacements. S.M. Kurtz, R. Gsell, and]. Martell, Eds. West Conshohoken, PA American Society for Testing and Materials. 

Recently, it has been found that the temperature in articulated joints may rise up to 45° C below the cartilage surface in vivo [23,24] and up to 90° C in ex vivo hip-joint simulator tests [25,26]. Irreversible unfolding of proteins occurring under such conditions can significantly affect their boundary lubrication properties. 

Essner A, Schmidig G, Wang A. The clinical relevance of hip joint simulator testing In vitro and in vivo comparisons. 

Joint simulator testing and wear debris osteolytic potential will be the subject of future studies. 

Walter A. Wear-screening of ceramic-to-ceramic components for total hip replacements by ring-on-disc device and joint simulator test. In High tech ceramics. Amsterdam Elsevier Science Publishers B.V. 1987. 

Rheology of joint simulator test fluids (to be submitted). 

In joint simulator testing it is usual to plot wear (mm ) against the number of test cycles (10 ), and the curve is similar in form to that displayed in... 

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