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.

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

Solid elements have 3 degrees of freedom (DOF) because they can only deform in 3 directions.

• Solid elements are used to model objects that are not easily deformed in all directions

• The 3 DOF are translations in x, y, and z directions

• Examples include beams, columns, and plates

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

The number of frequencies should be chosen based on the complexity of the model and the desired level of accuracy.

• Consider the size and complexity of the model - more frequencies may be needed for intricate geometries

• Balance between computational time and accuracy - higher number of frequencies increases computation time

• Perform convergence studies to determine the minimum number of frequencies required for accurate results

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.

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 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