Esin Coskuner- 503091330 (5th week unanswered word)

9.Tube splitting method

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Tube Splitting Method (March 19, 17:43)( Previous):

Tube splitting is a problem involving plastic bending/stretching and tearing. When tubes axially split, they are efficient in absorbing energy and sustaining long stroke (up to 90% of tube length). In this arrangement, a tube sits on a die while compressed at the top with a plate. A curl stopper plate may be used to prevent curl formation and to enhance the axial force.

(Zhang, L., Engineering Plasticity and Impact Dynamics, p. 61)

Tube Splitting Method(New-Better)(Specimen Control Method)

Figure 1(a) illustrates the splitting method[4]. A deep cut is sawn into the specimen and the opening(or possibly the closing) of the adjacent material indicates the sign and approximate size of the residual stresses present. This method is commonly used as a quick compaarative test for quality control during material production. The ‘prong’ test shown in Figure 1(b) is variant method used for assessing stresses in dried lumber [5].

The splitting method is often used to assess the residual stresses in thin-walled tubes. Figure 1 shows two different cutting arrangements [6], (c) for evaluating longitudinal stresses and (d) for circumferential stresses. The latter arrangement is commonly used for heat changer tubes, and is specified by ASTM standard E1928 [7].

The thin-wall tube splitting method illustrated in Figures 1(c) and (d) is also an example of Stoney’s Method [8] , sometimes called the curvature of a thin plate caused by the addition or removal of material containing residual stresses. The method was originally developed for evaluating the stresses in electroplated materialls, and is also used for assessing the stresses induced by shot-peening [9].

(Experimental and Applied Mechanics: Proceedings of the 2010 Annual Conference on Experimental and Applied Mechanics, pg 222,2011,Editor:Tom Proulx)