Aerospace Pressure Vessel Random Vibration Analysis
Budget: $30 – $250 USD
Job Posting: Random Vibration (PSD) Analysis for Aerospace Pressure Vessel using MSC Nastran/Patran Overview: We are seeking an experienced Structural Dynamics / Simulation Engineer proficient in MSC Nastran/Patran to perform a comprehensive Random Vibration (PSD) Analysis on a spherical, welded pressure vessel assembly designed for an aerospace application.
Job Description & Scope:
• FE Modeling: Build a high-quality Finite Element (FE) model from the provided CAD geometry using Patran. The geometry consists of a spherical welded shell, equatorial mounting brackets, and polar sensor/filling bosses.
• Operational Conditions: The vessel operates under a high internal static pressure of 120 bar at an elevated temperature of 110°C. The fluid mass inside must be accurately accounted for in the dynamic model.
• Dynamic Analysis:
1. Perform a Normal Modes (Modal) Analysis to identify the primary natural frequencies and mode shapes of the assembly.
2. Run a Random Vibration Analysis using Nastran by applying a highly aggressive input PSD profile with an overall intensity of 28.56 GRMS (frequency range: 15 Hz to 2000 Hz, with a peak energy density of 0.682 g^2\Hz between 245 Hz and 655 Hz).
• Stress Evaluation: Extract and evaluate 1*sigma, 2*sigma, and 3*sigma RMS stresses and accelerations at critical locations (weld lines, mounting brackets, and sensor interfaces) to compute Margins of Safety against material yield and fatigue limits.
Required Deliverables:
1. Nastran Solved Files: Full delivery of the complete, solved input and output files (.bdf/.dat and .op2/.f06).
2. Parametric/Updatable Model: The FE model must be built robustly so it can be easily updated and rerun for different tube diameters, shell geometries, and wall thicknesses in subsequent design iterations.
3. Technical Report: A clean, professional aerospace-standard analysis report documenting the mesh convergence, boundary conditions, first 5 natural frequencies, RMS stress plots, and structural margins under combined internal pressure and PSD loads.
Qualifications:
• Proven track record with MSC Nastran and Patran in aerospace or defense industries.
• Deep understanding of random vibration theory, PSD data processing, and cumulative fatigue damage.
• Familiarity with environmental testing standards (such as MIL-STD-810H or RTCA DO-160G) is highly desirable.
Job Description & Scope:
• FE Modeling: Build a high-quality Finite Element (FE) model from the provided CAD geometry using Patran. The geometry consists of a spherical welded shell, equatorial mounting brackets, and polar sensor/filling bosses.
• Operational Conditions: The vessel operates under a high internal static pressure of 120 bar at an elevated temperature of 110°C. The fluid mass inside must be accurately accounted for in the dynamic model.
• Dynamic Analysis:
1. Perform a Normal Modes (Modal) Analysis to identify the primary natural frequencies and mode shapes of the assembly.
2. Run a Random Vibration Analysis using Nastran by applying a highly aggressive input PSD profile with an overall intensity of 28.56 GRMS (frequency range: 15 Hz to 2000 Hz, with a peak energy density of 0.682 g^2\Hz between 245 Hz and 655 Hz).
• Stress Evaluation: Extract and evaluate 1*sigma, 2*sigma, and 3*sigma RMS stresses and accelerations at critical locations (weld lines, mounting brackets, and sensor interfaces) to compute Margins of Safety against material yield and fatigue limits.
Required Deliverables:
1. Nastran Solved Files: Full delivery of the complete, solved input and output files (.bdf/.dat and .op2/.f06).
2. Parametric/Updatable Model: The FE model must be built robustly so it can be easily updated and rerun for different tube diameters, shell geometries, and wall thicknesses in subsequent design iterations.
3. Technical Report: A clean, professional aerospace-standard analysis report documenting the mesh convergence, boundary conditions, first 5 natural frequencies, RMS stress plots, and structural margins under combined internal pressure and PSD loads.
Qualifications:
• Proven track record with MSC Nastran and Patran in aerospace or defense industries.
• Deep understanding of random vibration theory, PSD data processing, and cumulative fatigue damage.
• Familiarity with environmental testing standards (such as MIL-STD-810H or RTCA DO-160G) is highly desirable.