20+ FEA Engineer Interview Questions and Answers

The number of zero natural frequencies in free-free modal analysis of hex elements.

• Free-free modal analysis

• Hex elements

• Zero natural frequencies

Materials properties required for thermal analysis

• Thermal conductivity

• Specific heat capacity

• Thermal expansion coefficient

• Melting point

• Boiling point

• Heat transfer coefficient

• Thermal diffusivity

Non-linearity convergence issue can be resolved by adjusting the solver settings and/or modifying the model.

• Check the initial conditions and boundary conditions

• Try using a different solver or adjusting the solver settings

• Modify the model to reduce non-linearity

• Check for any errors in the input data or model setup

• Increase the number of iterations or decrease the convergence tolerance

• Consider using sub-stepping or adaptive time-stepping

• Perform a sensitivity analysis to identify...read more

Quality checks for mesh include element size, aspect ratio, skewness, orthogonality, and boundary conformity.

• Element size should be appropriate for the geometry and physics of the problem.

• Aspect ratio should be within acceptable limits to avoid distorted elements.

• Skewness should be minimized to avoid numerical errors.

• Orthogonality should be maintained to ensure accurate results.

• Boundary conformity should be checked to ensure proper connection with adjacent meshes.

• Examples: Ja...read more

Mild steel has a gradual yield point and high ductility, while aluminum has a sharp yield point and low ductility.

• Mild steel has a gradual yield point, while aluminum has a sharp yield point.

• Mild steel has high ductility, while aluminum has low ductility.

• Mild steel can withstand more stress before breaking than aluminum.

• Aluminum is lighter than mild steel and has better corrosion resistance.

Low cycle fatigue occurs at high stress levels and a small number of cycles, while high cycle fatigue occurs at low stress levels and a large number of cycles.

• Low cycle fatigue is caused by plastic deformation and occurs at stress levels above the yield strength of the material.

• High cycle fatigue is caused by cyclic loading and occurs at stress levels below the yield strength of the material.

• Low cycle fatigue is typically seen in aerospace and automotive applications, while h...read more

Linear analysis assumes linear relationship between inputs and outputs, while non-linear analysis considers non-linear relationships.

• Linear analysis assumes small changes in inputs result in proportional changes in outputs

• Non-linear analysis considers complex relationships between inputs and outputs

• Linear analysis is simpler and faster, while non-linear analysis is more accurate

• Examples of non-linear analysis include material yielding, large deformations, and contact problems

Meshing is the process of dividing a complex geometry into small, simple shapes for analysis. Mesh convergence refers to achieving a stable solution as the mesh is refined.

• Meshing is the process of dividing a complex geometry into small elements called 'mesh' for FEA analysis

• Mesh convergence is the process of refining the mesh until the results of the analysis no longer change significantly

• Convergence criteria are typically based on changes in key output parameters such as st...read more

Types of elements in FEA include 1D, 2D, 3D, beam, shell, solid, and more.

• 1D elements are used for modeling rods and beams

• 2D elements are used for modeling plates and shells

• 3D elements are used for modeling solids

• Beam elements are used for modeling slender structures

• Shell elements are used for modeling thin structures

• Solid elements are used for modeling volumetric structures

• Other types of elements include axisymmetric, plane stress, plane strain, and more

Model analysis is performed by applying loads and constraints to a virtual model and analyzing its behavior using simulation software.

• Create a virtual model using CAD software

• Apply loads and constraints to the model

• Use simulation software to analyze the model's behavior

• Interpret the results and make necessary modifications to the model

• Repeat the process until desired results are achieved

Projects involve structural analysis, thermal analysis, modal analysis, and optimization using FEA software.

• Performing structural analysis to ensure components meet design requirements

• Conducting thermal analysis to study heat transfer and thermal stresses

• Modal analysis to determine natural frequencies and mode shapes

• Optimization studies to improve design performance and reduce weight

• Examples: analyzing a car chassis for strength, simulating heat dissipation in electronic comp...read more

Stress is the force applied to an object, while strain is the resulting deformation or change in shape.

• Stress is measured in units of force per unit area, such as pounds per square inch (psi) or newtons per square meter (N/m²).

• Strain is measured as a ratio of the change in length or shape of an object to its original length or shape.

• Stress and strain are related through a material's elasticity, which is the ability of a material to return to its original shape after being def...read more

Various types of analysis are carried out such as structural, thermal, fluid, and dynamic analysis.

• Structural analysis is used to determine the strength and stability of a structure under different loads.

• Thermal analysis is used to study the temperature distribution and heat transfer in a system.

• Fluid analysis is used to study the behavior of fluids and their interaction with solid structures.

• Dynamic analysis is used to study the response of a system to external forces and vi...read more

Nonlinear analysis is used to simulate the behavior of structures under extreme conditions.

• Nonlinear static analysis

• Nonlinear dynamic analysis

• Material nonlinearity

• Geometric nonlinearity

• Contact nonlinearity

• Examples: buckling, plastic deformation, impact analysis

Principal stress is the maximum or minimum normal stress acting on a plane at a point in a stressed body.

• Principal stress is a type of normal stress.

• It occurs on a plane where the shear stress is zero.

• The maximum and minimum principal stresses are perpendicular to each other.

• The principal stresses are important in determining the failure of a material.

• Examples of applications include designing structures and analyzing mechanical components.

Modal analysis is a technique used to study the dynamic behavior of structures by identifying their natural frequencies and mode shapes.

• Modal analysis helps in understanding how a structure will respond to dynamic loads.

• It involves calculating the natural frequencies and mode shapes of a structure.

• Modal analysis is commonly used in structural engineering, aerospace engineering, and mechanical engineering.

• The results of modal analysis can be used to optimize the design of stru...read more

A balanced composite is a material made up of two or more different materials with the purpose of combining their properties.

• Balance composites are designed to have specific properties such as strength, stiffness, and durability.

• Examples of balance composites include fiberglass, carbon fiber, and Kevlar.

• These composites are commonly used in industries like aerospace, automotive, and sports equipment.

Types of elements used in FEA include beam, shell, solid, and contact elements.

• Beam elements are used for 1D analysis of structures like beams and trusses.

• Shell elements are used for 2D analysis of thin structures like plates and shells.

• Solid elements are used for 3D analysis of solid structures like blocks and volumes.

• Contact elements are used to model interaction between different parts in a simulation.

Fatigue is the weakening of a material caused by repeated loading and unloading.

• Fatigue occurs when a material is subjected to cyclic loading, leading to cracks and eventual failure.

• It is a common issue in engineering, especially in structures subjected to dynamic loads like bridges and aircraft.

• Fatigue can be analyzed using techniques like Finite Element Analysis (FEA) to predict the lifespan of a component.

Coefficient of convection is a measure of the ability of a fluid to transfer heat to a solid surface.

• Coefficient of convection depends on the fluid properties, flow conditions, and surface geometry.

• It is typically denoted by 'h' and has units of W/(m^2*K).

• Higher values of h indicate better heat transfer between the fluid and solid surface.

• Examples of factors affecting h include fluid velocity, temperature difference, and surface roughness.

FEA solver type refers to the specific software or algorithm used to solve finite element analysis problems.

• Common FEA solver types include Abaqus, ANSYS, Nastran, and LS-DYNA

• Solver type selection depends on the specific analysis requirements and capabilities of the software

• Different solvers may have strengths in certain types of simulations, such as structural, thermal, or fluid analysis

Newton's three equations describe the relationship between forces and motion.

• First law: An object at rest stays at rest, an object in motion stays in motion unless acted upon by an external force.

• Second law: F = ma, where force is equal to mass times acceleration.

• Third law: For every action, there is an equal and opposite reaction.

FEA process involves pre-processing, solving, and post-processing steps to analyze the behavior of structures under different conditions.

• Pre-processing: Define geometry, apply boundary conditions, mesh generation

• Solving: Apply loads, solve equations, obtain results

• Post-processing: Interpret results, validate against experimental data, make design decisions