Advanced Stress Analysis

Overview

E²G|The Equity Engineering Group, Inc. performs stress analyses for the evaluation of in-service equipment and structures, and as consultants to manufacturers in the construction of new equipment. Building on the methods outlined in Part 5 of the ASME Boiler & Pressure Vessel Code Section VIII, Division 2 and API 579-1/ASME FFS-1, E²G is able to simulate and evaluate many different equipment conditions and loadings.

Stress Analyses Performed by E²G:

• Elastic stress analysis/inelastic stress analysis including the effects of material and geometric nonlinearity
• Evaluation for protection against plastic collapse using elastic stress analysis, limit load analysis, or elastic-plastic analysis using the MPC Universal Stress-Strain Curve model — consideration of load case combinations for all methods
• Local strain analysis using the elastic or elastic-plastic approach- the elastic-plastic approach may be assessed using a path independent or path dependent analysis
• Bifurcation buckling analysis based on an elastic equilibrium path, bifurcation buckling analysis based on an inelastic equilibrium path that includes the effects of material and geometric nonlinearity, and plastic collapse analysis
• Fatigue analysis using the elastic analysis method, the elastic-plastic analysis method, and the Battelle Verity™ method; consideration of the load histogram and cycle counting considered for all methods
• Ratcheting assessment using either elastic or elastic-plastic analysis
• Evaluation of high-temperature components based on inelastic analysis including the effects of plasticity and creep using the MPC Project Omega material model
• Creep buckling analysis using the MPC Project Omega material model for evaluation of permissible compressive stresses at high temperatures
• Transient or steady-state thermal analysis with temperature dependent properties and film coefficients for the solution of thermal gradients used in thermal stress analysis
• J-integral analysis for the assessment of crack-like flaws
• Coupled thermal, diffusion, and stress analysis for the evaluation and/or optimization of startup and shutdown cycles for heavy wall process vessels in hydrogen service
• Creep-fatigue evaluation using traditional interaction diagram approaches or the new MPC Modified Project Omega model developed for the proper evaluation of hold-time effects
• Dynamic analysis of components using direct integration or model superposition methods
• Earthquake analysis using response spectra techniques
• Forming analysis consideration large strain and elastic-plastic material models for evaluation of new fabrication (i.e., head forming, or dents in in-service components)
• Simulation of weld residual stress
• Simulation of cyclic loading considering cyclic plasticity material models.

E²G Modeling Addresses:

• Different types of welds including butt welds, fillet welds, nozzle attachment welds, repair welds, and stiffener and plate attachment welds
• All types of materials
• A full range of welding parameters including heat input, travel speed, and welding sequence
• Both 2D and 3D welded geometries including weld intersections and the evaluation of starts and stops in the welding process