By SysCAD Techno Solutions | CAE Experts for Structural Joint Integrity
In critical applications like offshore platforms, earth-moving equipment, pipelines, and structural steel systems, the reliability of welded and bolted joints is non-negotiable. These joints are the backbone of mechanical integrity—and simulation is the key to ensuring they’re strong, durable, and standards-compliant.
At SysCAD Techno Solutions, we deliver advanced CAE simulations for structural joints based on global codes, modern fatigue methods, and high-resolution FEA to ensure your components are safe, optimized, and certifiable.
Bolted Joint Simulation – Standard-Based & Precision Driven
Standards We Follow
• ASME BPVC Section VIII Div 1 – Bolt design in pressure vessels
• EN 1993-1-8 (Eurocode 3) – Structural bolt design criteria
• VDI 2230 Part 1 – Mechanical bolted joints with preload
• ISO 898-1 – Bolt material properties
• ISO 15048 – Non-preloaded structural bolts for steel structures
Simulation Features
• Preload application from torque (e.g., M20, Grade 10.9 bolt → 160 kN @ 300 Nm)
• Friction modeling with µ = 0.12–0.25 for realistic stick-slip behavior
• Gasket compression analysis to ensure sealing at pressures > 25 MPa
• Threaded contact behavior and load redistribution
• Fatigue under dynamic loading using Goodman, Soderberg corrections
• Bolt failure criteria based on von Mises and shear stress combinations
• Factor of safety ≥ 1.5 for fluctuating loads
Welded Joint Simulation – Thermal and Structural Accuracy
Welding Standards Implemented
• AWS D1.1 / D1.5 – Structural & bridge welding
• ISO 5817 / ISO 13919 – Weld quality assessment
• EN 1993-1-9 – Weld fatigue in steel structures
• API 1104 – Pipeline welding
• ASME Section IX – Welding qualification
• BS 7608 – Fatigue design of welded structures
Simulation Capabilities
• Weld bead and weld geometry modeling (fillet, butt, T, lap joints)
• Thermal cycle simulation (arc temp 6000–8000°C, cooling rate 5–50°C/s)
• Residual stress and distortion predictions
• Material property change in heat-affected zone (HAZ)
• Fatigue life prediction using S-N curves based on weld class
• Crack initiation and propagation analysis per BS 7910 / API 579
Weld Fatigue Simulation Methods
1. Nominal Stress Method (NSM)
• Based on BS 7608, Eurocode
• Uses global S-N curve for detail category (e.g., Category 80)
• Quick and suitable for simplified fatigue checks
2. Hot Spot Stress Method (HSSM)
• Identifies stress at weld toe using extrapolated surface stresses
• Applicable for offshore structures (DNV-RP-C203, IIW methods)
• Eliminates dependency on weld modeling
3. Effective Notch Stress Method (ENSM)
• Incorporates weld toe geometry with 1 mm radius
• High-fidelity modeling for accurate local stress
• Ideal for fatigue-critical, high-performance welded joints
4. Fracture Mechanics Approach
• Crack growth prediction using da/dN and Paris’ Law
• Validated with API 579 and BS 7910
• Used in maintenance & repair strategies for cracked welds
Technical Case Studies
• Excavator boom weld toe fatigue – Category 90, 5.2×10⁵ cycles, passed
• Flange bolt preload stress – 210 MPa, 1.1×10⁶ cycles, passed VDI 2230
• Oil skid bolted frame – 18% weight reduction after simulation
• Offshore riser weld root – ENSM simulation reduced hotspot stress by 32%
• Vibrating machinery joint – bolted connection redesigned for infinite life
Applications
• Pressure vessels and piping flanges
• Lifting equipment (cranes, booms, hooks)
• Structural steel connections (bridges, towers)
• Mining and construction equipment
• Heavy transport systems (rail, trailer chassis)
• Offshore platforms and jackets
• Earth-moving machinery frames
