Patent ID: 8688418

Claim:
A method for design verification and validation of surface and sub-surface oil and gas equipment components comprising the steps of: (a) analyzing the components for global static strength and local plasticity with an elastic-plastic finite element model, the analysis using preset load conditions and the least favorable combination of dimensional tolerances for each component based on an initial mesh density and comprising the steps of: (i) confirming that the design of the component results in a stable model convergence using all preset load conditions; (ii) conducting a mesh refinement study on stressed portions of the components, where further refinement in mesh density will result in less than a pre-selected mesh refinement percentage change in plastic strain; (iii) confirming that stressed portions of the components identified by the model have strain limit damage that is less than a set strain limit damage amount; (b) conducting a ratcheting assessment by running an elastic-perfectly plastic analysis with the model on all equipment components that exhibit local plasticity at a maximum combination of preset load conditions to determine resistance to ratcheting by applying the maximum preset load conditions to such components to demonstrate at least one ratcheting criterion; and (c) examining all components to determine fatigue sensitive locations and subjecting components exhibiting fatigue sensitive locations to a fatigue analysis.