Stress concentration factors and elastic-plastic stress and strain predictions for axisymmetric internal projections on hollow tubes subjected to axial loading

Abstract

The finite element method has been used to obtain stress concentration factor data for hollow tubes with axisymmetric internal projections subjected to axial loading. A range of geometries has been considered in the investigation, and the results are complementary to previously published data. Preliminary results from an elastic-plastic analysis of a component with an internal projection are presented. Strain predictions with an elastic-perfectly-plastic material model are found to be between those estimated using linear and Neuber rules for low cycle fatigue life predictions. 45 0309-3247/89/0100-0045 $02.00

Elastic and elastic-plastic finite element analysis of hollow tubes with axisymmetric internal projections under combined axial and pressure loading

“…This ratio is slightly smaller than the value predicted for ìˆ0 , çˆ0 :5 (i.e. 0.7 from reference [4]). …”

“…case 2), with results from reference [4] for purely axial loading. It is seen that greater plastic deformation occurs during loading but a similar, much smaller residual compressive stress field is established when the axial load is removed.…”

“…In this analysis one geometry is selected (i.e. geometry 1 from reference [1]) which has a moderate SCF [4]. For geometry 1, D=tˆ10, h=tˆ2:5, T =tˆ1:5 and r=tˆ0:08.…”

“…13b. Again, the corresponding results for ìˆ0 , çˆ0 :5, taken from reference [4] are included and it can be seen that the effect of sustained internal pressure on the size of the compressive yield zone is small. The corresponding residual stress distributions at the Gauss points nearest to the inside surface are given in The last two rows of Table 4 quantify the effect of the sustained internal pressure on the residual stress predictions in the fillet and tube end for çˆ0 :5 and demonstrate that the internal pressure slightly reduces the compressive meridional and hoop stresses in the fillet.…”

Upper and lower bound limit and shakedown loads for hollow tubes with axisymmetric internal projections under axial loading

“…Finite element predictions have been obtained using the ANSYS suite of programs [11] for the four sets of geometric parameters shown in Table 1. These four geometries have previously been the subject of elastic and elastic-plastic (low-cycle fatigue) analyses (see, for example, references [12] and [13]) from which the elastic stress concentration factors given in Table 1 are taken.…”