Use the following guidelines to help choose the correct analysis type for your situation.
Linear
Static Stress with Linear Material Models
- Calculate the displacements and stresses due to static loads.
- The magnitude or direction of the loading will not change over time.
- No inertial effects. The mass of the model is used to determine loads, such as gravity and centrifugal forces.
- Although contact is a nonlinear effect, it can be included in a static stress analysis. The solution becomes iterative.
- Examples: structures (buildings, car frames, truss systems), bodies (valve bodies, ship hulls, housings, support brackets, pressure vessels), press-fits.
Natural Frequency (Modal)
- Calculate the natural frequencies and mode shapes of the model due to purely geometric and material properties.
- Examples: structures (buildings, bridges, towers), shafts, bodies (housings, support brackets).
Natural Frequency (Modal) with Load Stiffening
- Calculate the natural frequencies and mode shapes of the model due to purely geometric and material properties.
- Axial compressive or tensile loads affect the frequency of the system.
- Examples: structures (buildings, bridges, towers), shafts, bodies (housings, support brackets).
Response Spectrum
- Calculate the maximum displacements and stresses due to a spectrum-type load.
- Examples: structures subjected to earthquakes, blast and shock loads, and so on.
Random Vibration
- Calculate the statistical response of a system (displacements and stresses) due to a random vibration, white noise, or a power spectrum density.
- Examples: suspension systems, aerospace components, fans, and pumps.
Frequency Response
- Calculate the steady state response (displacements and stresses) due to a harmonic or sinusoidal load or acceleration.
- Examples: structures with rotating imbalance, frequency sweeps, fans, and pumps
Transient Stress (Direct Integration or Modal Superposition)
- Calculate the displacements and stresses over time due to loads that will vary in a known fashion.
- Inertial effects are included.
- Examples: structures subjected to transient events (buildings, bridges, towers), bodies (housings, support brackets), rotating imbalance.
Critical Buckling Load
- Calculate the load that causes your model to buckle due to geometric instability.
- No inertial effects. (The mass of the model is used to determine loads, such as gravity and centrifugal forces.)
- Examples: column designs, structures (buildings, bridges, towers).
Dynamic Design Analysis Method (DDAM)
- Use when you want to calculate the maximum displacements and stresses due to a spectrum-type load.
- Use when designing naval equipment or vessels.
- Examples: exhaust uptakes, masts, propulsion shafts.
Nonlinear
The assumptions listed for linear analyses are not limitations when doing a nonlinear analysis. Unless indicated otherwise, nonlinear permits the following:
- The loading can cause large deflections and/or rotations.
- Rigid body motion and/or rotations are accounted for.
- The loading can change in direction due to the deformation.
- The materials can be nonlinear, either elastic (such as rubber) or plastic (such as a metal that exceeds the yield strength).
- The boundary conditions can change over time in a known fashion.
MES (Mechanical Event Simulation) with Nonlinear Material Models
- Calculate the displacements, velocities, accelerations, and stresses over time due to dynamic loads.
- The loads can be constant, vary over time, or vary based on calculated results.
- Inertial effects are included.
- Examples: linkages and mechanisms, press-fit, snap-fits, multiple body contact and impact, forming and extruding processes, rubber and foam components (bellows, seats).
Static Stress with Nonlinear Material Models
- Calculate the displacements and stresses due to static loads.
- The loads can be constant, vary between time steps or load cases, or vary based on calculated results.
- Inertial effects are ignored. (The mass of the model is used to determine loads, such as gravity and centrifugal forces.)
- Examples: press-fit, multiple body contact and impact, forming and extruding processes, rubber and foam components (bellows, seats).
Natural Frequency (Modal) with Nonlinear Material Models
- Calculate the natural frequencies and mode shapes of the model.
- The change in frequency due to displacements or changing material properties is not included.
- Loads do not affect the frequencies.
- Boundary conditions are fixed.
- Examples: structures (buildings, bridges, towers), shafts, bodies (housings, support brackets).
MES Riks Analysis
- Calculate the displacements and stresses before and after the model has buckled or collapsed.
- Inertial effects are ignored.
- Examples: columns, components with snap-through behavior.
Thermal
Steady State Heat Transfer
- Calculate temperature and heat fluxes after an infinite period (steady-state conditions).
- The thermal loads are constant over time.
- Examples: structures (furnaces, insulating wall), electrical components.
Transient Heat Transfer
- Calculate the temperature and heat fluxes over time due to the thermal loads.
- The thermal loads can be constant or change over time.
- The material can change states between a solid and liquid.
- Examples: structures (furnaces, insulating walls, brake systems), electrical components, annealing processes.
Electrostatic
Electrostatic Current and Voltage
- Calculate the current and voltage distribution after an infinite period (steady-state conditions) due to induced voltages and current sources.
- Examples: electrical components (circuit breakers, circuit boards, batteries), piezoelectrics.
Electrostatic Field Strength and Voltage
- Calculate the electric field and voltage distribution after an infinite period (steady-state conditions) in an insulator due to induced voltages and charges.
- Examples: insulators, micro electro mechanical systems (MEMS)