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Finite element analysis for pressure equipment, structures and piping.
Design by analysis where the rule equations cannot reach — carried out in industry-trusted software and assessed against the governing code.
Section 01
Finite Element Analysis to ASME Sec VIII-2 Part 5
Design by analysis for geometry and loading the design-by-rule equations cannot address. We perform the assessments required by Part 5 using industry-trusted software, applying the method appropriate to the failure mode and the level of demonstration required.
Part 5.2
Protection against plastic collapse
Elastic stress analysis with linearisation and categorisation, limit-load analysis using elastic-perfectly-plastic material and small-displacement theory, or nonlinear elastic-plastic analysis with a true stress-strain curve and large-displacement effects.
The elastic-plastic route generally gives the least conservative result, and is used where geometry makes stress categorisation unreliable.
Part 5.3
Protection against local failure
Assessed by either route. The elastic method checks the sum of the three principal stresses against the limit, giving a quick screen but no credit for redistribution. The nonlinear elastic-plastic method evaluates the limiting triaxial strain, accounting for stress triaxiality and accumulated plastic strain, and is the route to take where the elastic check fails or where geometry is sharply discontinuous.
Both are applied at nozzle junctions, thickness transitions and weld toes.
Part 5.4
Protection against collapse from buckling
Bifurcation and collapse assessment for external pressure, vacuum, axial compression and combined loading, with the design factor applied according to the analysis type used.
Part 5.5
Protection against failure from cyclic loading
Fatigue assessment by elastic stress, elastic-plastic strain, or the structural stress method for welds, with cycle counting from the operating histogram. Ratcheting assessed by elastic analysis, or by elastic-plastic cyclic analysis where a stable state has to be demonstrated.
Load case
Seismic analysis
Modal extraction and response spectrum analysis for vessels, columns and equipment, with equivalent static methods where the structure is regular enough to permit them and time-history analysis where the project demands it. Covers support and anchorage reactions, base shear distribution, sloshing loads in partially filled vessels, and interaction between the equipment and its supporting structure.
Analysis is carried out to the requested seismic code, and results are assessed against Part 5 criteria as occasional loads.
Load case
Rigging analysis
Lifting, tailing, upending and transport conditions, which frequently govern the design of thin-walled or long vessels. Covers local stress at lifting lugs and trunnions, shell stability during the lift, sling angle effects, dynamic amplification and tailing lug loads.
Section 02
Steel Structure Analysis and Civil Design
Analysis and design of bolted and welded steel structures, and the civil works supporting them, carried out in industry-trusted software.
Member design
Axial tension and compression, flexure, shear and combined actions. Local buckling and section classification. Lateral-torsional buckling of unrestrained beams. Effective length and stability assessment, including second-order P-Δ and P-δ effects where the structure is slender or lightly braced. Built-up and plate girder sections where rolled sections are not adequate.
Bolted connections
Bearing-type and slip-critical joints. Bolt shear, tension and combined interaction. Prying action in tension connections, which is where hand calculations most often fall short. Block shear, edge distance and spacing. Eccentric bolt group analysis. Splice and moment end-plate design.
Welded connections
Fillet and groove weld sizing, weld group analysis under combined force and moment, base metal capacity at the connection, weld access and sequencing, and fatigue classification of welded details where the structure carries cyclic or vibrating load.
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