RP2Z Software Module Development for Modeling Multi-Bead and Multi-Layer Welding

Recently, EWI in collaboration with the Ohio Supercomputer Center (OSC) developed E-Weld Predictor,™ an on-line weld modeling tool. E-Weld Predictor allows welding and design engineers to simulate arc welding processes to predict microstructure, thermal profiles, residual stress, and distortion for plate and pipe welding. Attempts were taken to apply E-Weld Predictor to simulate the temperature evaluations during RP2Z weld procedure development. RP2Z, standing for API Recommended Practice 2Z (RP2Z), is a standard for preproduction qualification for steel plates for welded offshore structures.

A prototype of RP2Z software module was developed in a EWI Cooperative Research Project (CRP). This module provided the flexibility for a user to define weldment geometry, individual bead shape, and complex bead layup. The user can obtain the individual bead shape by digitizing a weld bead profile into a series of XY coordinates from a weld cross section macrograph. The RP2Z module imported those weld bead profiles and weldment geometry to automatically generate a finite element mesh for thermal analysis as shown in Figure 1. Figure 2 shows the predicted temperature distribution for a mock-up RP2Z test. The gray area (above 1500°C) is assumed to represent the weld metal while the red area (between 1250 and 1500°C) is assumed to represent to the coarse-grain HAZ. Currently, the accuracy of temperature predictions is being validated with experimental data. Further improvement will be done during continual development of the software module. The software module can be installed in a user local computer.

The RP2Z software module expands E-Weld Predictor capabilities. It gives a user flexibility to define weld bead shapes and it is possible to analyze other weld joints besides butt joint in the current E-Weld Predictor. The software module can be customized based on a user’s requirement and installed locally in a user’s computer. For more information on the software module, contact yyang@ewi.org or call 614.688.5253 and for more information on E-Weld Predictor, contact skhurana@ewi.org or call 614.688.5250.