Dynamic F.E.A. of High-Pressure Metal Seal

About the project

REQUEST FOR QUOTATION: Nonlinear FEA of an Ultra-High-Pressure Cylinder and Seal Interface Project Title: Nonlinear FEA & Fatigue Life Analysis – Ultra-High-Pressure Cartridge Holder Company: Quantum SPT Background Quantum SPT designs and manufactures ultra-high-pressure water pumps. We are seeking an experienced FEA engineer to perform a nonlinear structural and fatigue analysis of a cartridge holder used within an ultra-high-pressure pump assembly. Operating pressure ranges from approximately 200–500 psi inlet pressure to 87,000 psi (approximately 600 MPa / 6,000 bar) outlet pressure, cycling at approximately 100 cycles per minute. The primary purpose of this project is to determine the stresses, deformation, failure mechanism and expected fatigue life of the cartridge holder. Quantum has many years of experience with the other components within this assembly. We are not seeking structural or fatigue-life analysis of those components. The surrounding cylinder, seal and mating components should therefore only be modelled to the extent necessary to accurately reproduce the loads, contact conditions, preload and mechanical interactions imposed on the cartridge holder. Objectives The analysis should: Determine the complete load and stress state imposed on the cartridge holder throughout the operating pressure cycle. Include the effects of assembly preload, component contact, seal behaviour and internal pressure where these affect cartridge-holder loading. Identify stress concentrations and fatigue-critical locations within the cartridge holder. Determine whether local yielding/plastic deformation occurs and its effect on subsequent pressure cycles. Estimate cartridge-holder fatigue life at approximately 100 cycles per minute. Report fatigue margin at 1,000 operating hours (approximately 6 million cycles) and predicted life to crack initiation. Where appropriate, recommend practical geometry, material or other design changes to improve cartridge-holder fatigue life. Scope of Analysis 1. Nonlinear structural/contact model Develop an appropriate nonlinear FEA model of the cartridge holder and sufficient surrounding assembly to accurately reproduce its real operating conditions. The model should consider, where applicable: Elastic-plastic material behaviour Assembly preload Contact between components Friction Hard seal/contact behaviour Pressure penetration into relevant interfaces Loading and unloading through the complete pressure cycle Residual stresses resulting from autofrettage where these materially affect loads transferred to the cartridge holder The surrounding components do not require detailed stress or fatigue assessment unless required to establish the correct boundary conditions or load transfer into the cartridge holder. The consultant should use 2D axisymmetric modelling where appropriate and 3D modelling where geometry or loading requires it. 2. Pressure cycling / dynamic behaviour Operating pressure cycles between approximately 200–500 psi and 87,000 psi at approximately 100 cycles per minute. The consultant should determine whether quasi-static nonlinear load stepping adequately represents the cartridge-holder loading or whether transient/dynamic analysis is necessary. If transient analysis is considered necessary, please explain why and identify the additional cost separately. 3. Cartridge-holder fatigue analysis Estimate fatigue life at critical locations within the cartridge holder. The proposal should identify the intended fatigue methodology, such as stress-life, strain-life, fracture-mechanics or another appropriate approach. The fatigue assessment should appropriately consider: Mean stress Multiaxial stress state Stress concentrations Residual stress where relevant Any local plasticity Material fatigue properties The actual operating pressure cycle The primary required outputs are: Predicted fatigue life to crack initiation Margin at 1,000 hours / approximately 6 million cycles Identification of the likely fatigue initiation location and failure mechanism Recommended cartridge-holder design changes where required Mesh Validation Mesh refinement should be concentrated on the cartridge holder and its critical interfaces. A mesh-convergence/sensitivity assessment should be performed at the locations used for stress and fatigue-life predictions to demonstrate that the results are not primarily mesh-dependent. Detailed mesh convergence of surrounding components is not required unless necessary for accurate cartridge-holder loading. Information Quantum Will Provide Following execution of an NDA, Quantum can provide: STEP CAD geometry of the cartridge holder and relevant surrounding components Material specifications and heat treatment Assembly and preload information Seal/interface details Autofrettage information relevant to the assembly Pressure waveform and cycle information Existing test data, including operating hours, pressures and observed failures, where available Photographs/details of actual failed components for correlation where available Deliverables We require: FEA model showing cartridge-holder loading and deformation Stress/strain results at critical cartridge-holder locations over the operating pressure cycle Identification of likely failure initiation locations and mechanisms Cartridge-holder fatigue-life prediction Fatigue margin at 1,000 hours / approximately 6 million cycles Relevant mesh-convergence results Design-change recommendations where appropriate Engineering report describing methodology, assumptions, results and conclusions Native FEA model files and associated input/output files Online results-review meeting with Quantum engineers Quotation Requirements Please provide: Fixed-price or not-to-exceed cost, preferably separated into structural/contact analysis and fatigue analysis Hourly rate for additional work Estimated completion time Proposed FEA software/solver Proposed element types and contact methodology Proposed fatigue methodology Key assumptions and exclusions Any additional information required from Quantum before commencing Please also briefly describe at least two relevant previous projects involving one or more of the following: Ultra-high-pressure equipment Thick-walled pressure cylinders Nonlinear contact Metal-to-metal/hard sealing interfaces Autofrettage/residual stress High-cycle fatigue Fatigue failure investigation General descriptions are acceptable where previous work is confidential. Important – Relevant Experience This is not a basic linear static FEA project. The component operates at pressures approaching 600 MPa / 87,000 psi and is subject to millions of pressure cycles. We are therefore looking for an engineer with demonstrated experience in nonlinear mechanical FEA and fatigue analysis, preferably involving high-pressure equipment. Please do not apply if your experience is primarily limited to basic linear static FEA. Confidentiality and Intellectual Property The initial project discussion can be conducted using general information. An NDA must be signed before detailed CAD, material specifications, proprietary design information or test data are provided. All analysis results, reports and FEA models produced specifically for this project are to become the property of Quantum SPT upon payment.

Skills required