Thermal Analysis of the Girth Weld of an Elastomeric Diaphragm Tank

J. VINCENT; J.M. CARELLA ; A.P. CISILINO

JOURNAL OF MATERIALS PROCESSING TECHNOLOGY

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 2014 vol. 214 p. 428 - 435

0924-0136

It is presented in this paper the thermal analysis of the girth weld joint of a titanium-alloy elastomeric diaphragm tank. The objective is to develop of a welding process that preserves the integrity of the elastomeric diaphragm. The analysis is based on a three-dimensional finite element analysis (FEA) which accounts for the latent heat due to phase changes, the dependence of the material properties on temperature and the effects of the convection in the weld pool. The parameters of the heat input model for the weld arc were calibrated using experiments. Towards this end, a series of AISI 304 plates were welded while monitoring the time evolution of their temperature fields using thermocouples and a thermographic camera. The extents of the molten pools, which were meassured via macro etch testing, were also used for the calibration of the heat-input parameters. The FEA model was then used to analyze the temperature field in the tank girth weld under various hypotheses for the contact heat conduction between the hemispheres and the retaining ring. The results of the analysis demonstrate the convenience of using a annular heat sink to make sure the thermal integrity of the polymeric diaphragm, regardless the effectiveness of the contact between the retaining ring and the hemispheres.