FEA[Finite Element Analysis]


Introduction:

Engineers have the unenviable position of being held entirely responsible for the integrity and safety of all the products and structures they design. Small miscalculations in design often lead to imminent disasters( that constantly go to court and get litigated). This is why products and structures go through an array of stress testing and optimization before being stationed in the real world. But doing so over hundreds of iterations( and to scale) can be prohibitively expensive. So masterminds frequently look to simulation modeling techniques( like Finite Element Analysis) to automate and simplify this testing This helps to reduce the use of accouterments for iterative prototyping, which would otherwise. So most of the engineers use finite element analysis for testing stress on their design.

What is FEA(Finite element Analysis)?

The important operation of CAD software is carrying out engineering analysis. Checking the designed object for its functionally is called as engineering analysis. In nearly all the engineering design related systems some or the other analysis is needed. It can be stress- strain computations, heat transfer measures, or using differential equations to find the dynamics of the system, which is being designed.


One of the most common of engineering analysis is finite element analysis or FEA. FEA is one of the most generally used and important point of the CAD software. It's a numerical fashion used to break engineering problems with an array of drugs- grounded computations. Finite element analysis( FEA) is a motorized system for how a product reacts to real- world forces, vibration, heat, fluid inflow and other physical goods. Finite element analysis shows whether a product will break, wear out or work the way it was designed. It's called analysis, but in the product development process, it's used to predict what is going to be when the product is used.

Finite element analysis (FEA) refers to the process of using mathematical calculations, models, and simulations to understand, analyze, and predict the behavior of an object, part, assembly, or structure under various physical conditions. FEA is typically used by engineers to model physical forces that help them identify vulnerabilities in the design of their product prototypes. It allows them to localize the design problems and optimize the components, thereby streamlining the design phase of the product. Potential design issues may refer to identifying overheating parts, weak spots, or areas of tension.


For example, an engineer designing a bridge will need to predict the behavior of the structure under load. The system of equations describing the distribution of structural stresses may be known, but cannot be easily (or directly) solved for a complicated structure such as a bridge. To carry out the analysis of an object by using FEA, the object is divided into a finite number of small elements of shapes like rectangular or triangular.

Finite element analysis helps predict the behavior of products affected by many physical effects, including:

  • Mechanical stress 
  • Mechanical vibration 
  • Fatigue 
  • Motion 
  • Heat transfer
  • Fluid flow 
  • Electrostatics
  • Plastic injection molding

Methodology of finite element analysis:

Finite Element System is generally used in FEA to compute approximate results of boundary problems( field problems) in engineering.


“ The field ” typically represents a physical structure as the main sphere.


“ Field variables ” are the variables of interest that are governed by a differential equation. They must achieve a boundary condition for specific values of the variables( or related variables)


A “ node ” is a specific point on the finite element that contains the value of the field variable-- that's typically explicitly calculated. These values are also used to calculate values nodal points through interpolation of values at the bumps using shape functions.


To carry out the analysis of the whole object each and every knot of the network is anatomized and their results are synthesized to get the complete analysis of the object. Each and every knot can be anatomized for colorful parcels like stress- strain, heat transfer or any other characteristics depending upon the type of operation. The interrelating behavior of all the bumps gives the behavior of the whole object.

FEA workshop by breaking down a real object into a large number( thousands to hundreds of thousands) of finite rudiments, such as little cells. Mathematical equations help predict the geste of each element. A computer also adds up all the individual actions and gives a clear picture.


Generic process for FEA


1. Preprocessing for Manufacturing


This stage requires you to define the sphere problem, material parcels, geometric parcels, mesh model, boundary conditions and the element types. generally at this stage, the mastermind will simplify the problem as much as possible to get quick yet accurate results.

For illustration, prior to simulation, a CAD model may have lots of filets, holes, or other features that are essential to the simulation-- but features that overeater computational coffers and increase render times. masterminds generally remove these features to speed up their simulations.

This can be done manually( with contrivers going by and removing these features one by one)-- or automatically using CAD defeaturing on Spatial software. One big advantage of automating this process is the reduction of human error.



2. Post-processing

Sorting, conniving, and printing is the final set of conditioning where your named results are enforced as results to your finite element analysis.


Finite element method:

Potential Energy method:
 
The potential energy method can also be used in finite element analysis (FEA), a numerical method for solving problems involving the behavior of materials and structures. In FEA, potential energy is often used as a measure of the internal forces and deformations within a structure.

Π = strain energy(U) + work potential (WP)

For example, consider a beam that is subjected to a load at one end. The potential energy of the beam can be calculated by analyzing the forces acting on the beam and the deformation of the beam due to the load. To use the potential energy method in FEA, we must first identify all of the forces acting on the beam and determine the potential energy associated with each force. For example, the force of gravity would contribute to the potential energy of the beam due to the weight of the beam itself. In addition, the load applied to the beam would also contribute to the potential energy, as it would cause the beam to deform and stretch. Once all of the potential energies associated with the forces acting on the beam have been calculated, they can be combined to determine the total potential energy of the beam. This total potential energy can be used to determine the internal forces and deformations within the beam, as well as the overall stability and strength of the beam. In summary, the potential energy method can be used in FEA to calculate the internal forces and deformations within a structure. This method involves analyzing the forces acting on the structure and determining the potential energy associated with each force, which can then be combined to determine the total potential energy of the structure.

Example:





Rayleigh-Ritz method:

The Rayleigh-Ritz finite element method is a numerical technique used to solve problems in structural mechanics and other fields. It is a type of finite element analysis, which is a method for solving partial differential equations by dividing the domain of the problem into small, manageable pieces called elements. In the Rayleigh-Ritz method, the elements are assumed to have a simple shape, such as a line or a rectangle, and the solution to the problem is approximated using a set of trial functions. This approach allows for the efficient solution of many types of problems, such as the analysis of stresses and strains in a structure or the calculation of the frequencies at which a structure will vibrate.

Suppose we want to find the natural frequencies of a cantilever beam with a rectangular cross-section. The beam is clamped at one end and has a uniform cross-section along its length. We can divide the beam into several elements, each with a rectangular cross-section. For each element, we can assume that the displacement of the beam is described by a trial function of the form:

u(x) = a + bx + cx^2 + dx^3

where a, b, c, and d are constants that we need to determine. We can then use the principle of minimum potential energy to find the values of these constants that will give us the best approximation to the true solution of the problem.

First, we need to calculate the potential energy of the beam for each element, using the trial function and the known properties of the beam (such as its cross-sectional area, Young's modulus, and so on). We can then use the principle of minimum potential energy to find the values of a, b, c, and d that will give us the minimum potential energy for each element.Once we have determined the values of a, b, c, and d for each element, we can use these values to construct the global stiffness matrix for the beam. This matrix contains information about the stiffness of the beam at each point, and can be used to find the natural frequencies of the beam.

In this way, the Rayleigh-Ritz finite element method allows us to efficiently approximate the natural frequencies of the beam and to determine its response to external loads.

Galerkin's method :


Galerkin's method is a mathematical technique that is commonly used in the analysis of differential equations, such as those that arise in the study of structural mechanics, fluid dynamics, and heat transfer. It is a type of weighted residual method, which means that it involves representing the solution to a differential equation as a weighted sum of known functions, or "basis functions."

To use Galerkin's method, we first need to choose a set of basis functions that are suitable for representing the solution to the differential equation that we are interested in. These basis functions should be chosen based on the particular characteristics of the problem, such as the boundary conditions, the nature of the solution, and the properties of the material.

Next, we need to write the differential equation in a suitable form for Galerkin's method. This typically involves multiplying both sides of the differential equation by a weighting function and integrating over the domain of the problem.

Once the differential equation has been written in this form, we can use Galerkin's method to approximate the solution by expanding it as a weighted sum of the chosen basis functions. This involves substituting the expansion into the weighted differential equation and solving for the coefficients of the basis functions.

Once the coefficients of the basis functions have been determined, we can use them to reconstruct the approximate solution to the differential equation. This solution can then be used to calculate various quantities of interest, such as the forces and stresses in a structure or the velocity and pressure in a fluid.

Overall, Galerkin's method is a powerful and versatile technique that can be used to solve a wide range of differential equations, making it a valuable tool in many areas of engineering and science.




Finite Element Analysis operations in CAD:


FEA is among the most important and generally used features in CAD design.

It's integral to CAD for assaying an object through the use of finite rudiments that include small blockish and triangular shapes. To dissect the whole object, each finite element in the whole object network is anatomized, and the issues are combined to plot the overall behavior of a complex object. Each element can be anatomized for certain property thresholds like stress- strain, dynamics, thermal parcels or any other characteristics( depending on where it's applied).In a CAD workflow, you can define each element and network structure as you bear in your design.


Why FEA software is useful:


FEA allows masterminds to conduct the simulation of a designed model rather than having to produce a physical model for testing purposes.


FEA offers further advantages.


FEM during analysis allows modeling of a different number of material types, and the capability to cover how confined goods impact a small area of design in complicated figure.

Engineers can use software specialized for finite element modeling for a wide range of tasks.

Fluid dynamics, distortion of a vehicle from collision and stress on mortal bones are some of the practical application of finite element modeling software.


Uses of Finite Element Analysis:


Finite element analysis is used across all core industries, including aerospace, industrial engineering, manufacturing, dentistry, biomechanical research, CFD, and plenty of others, mainly for the following reasons:

1. Offers digital prototyping

Creating a physical prototype to determine the stresses that the real world exerts and how objects react to them can be an expensive process. Instead, FEA allows you to develop a digital model for the object and study the stresses it encounters in the real world.


2. Provides easy visualization

With FEA, you can model the interior and exterior of an object, thereby allowing you to point out design flaws that are vulnerable to external conditions. As such, users can correct such design problems through finite element analysis that enables the visualization of stresses, strains, and thermal variations.


3. Applies boundary conditions

FEA allows you to study how the developed digital prototype responds to boundary conditions such as external forces, thermal effects, applied heat, and positional constraints.


4. Accurate object modeling

FEA software-based simulation models are far more accurate than physical models that are developed manually. This is why FEA has been the preferred option for most engineers, designers, and others.

Let’s understand how FEA is specifically used by each industry.

1. Automotive industry:


In the automotive industry, FEA software is used for various applications such as assessing the design components of an automobile, including the brakes, suspensions, bonnet, or other bodywork. Moreover, it also helps in carrying out virtual crash tests to better understand the performance of the vehicle design in a simulated crash-like situation.


2. Civil engineering:


FEA techniques are used to check the response of structures such as buildings, roads, and bridges to various topographical and environmental conditions. It allows you to design complex structures with complete safety.


3. Industrial equipment:

FEA is essential in designing and building durable industrial equipment such as tanks, pipes, etc. It allows you to predict how external heat pressure can deform tanks, pipes, or vessels, and how much force such equipment can endure to stay intact without getting affected.


4. Manufacturing industry:


In the manufacturing sector, FEA software allows designers to get a sneak-peak into the future performance and behavior of components such as metals before developing prototypes. Such a practice saves businesses from investing their time, effort, money, and resources in ineffective product designs. With finite element analysis, you can forecast whether the designed part will remain free from fractures or physical damage in the foreseeable future. The approach helps companies improve their ROI, shorten design cycles, reduce design costs, and boost overall design productivity.


5. Aerospace industry:


The aerospace industry uses FEA primarily for structural analysis. It is used for studying the aero-servo-elastic stability of aircraft, analyzing aircraft shapes, and determining the natural vibrational frequencies of aircraft components. Moreover, FEA also helps forecast and analyze aircraft behavior or reaction to structural deformity and thermal loads.


6. Biomechanical research:


Finite element analysis is a handy tool to reconstruct complex geometrical structures such as the natural and artificial tissues of humans. As FEA relies on mathematical functions and calculations, it aids in developing a complete understanding of craniofacial biomechanics and its analysis.

7. Dentistry:

FEA helps in simulating the geometry and surface structure of dental implants. It allows you to understand the material features of the implant, jawbone, and implant-jawbone interface. This analysis method is key to determining the success and failure of dental implants in clinical conditions. Moreover, users can also employ advanced image techniques to learn the effect of the applied mechanical forces on living bone tissues and their subsequent responses.

Advantages:

  • Modeling of complex geometries and irregular shapes are easier as varieties of finite elements are available for discretization of domain.

  • Boundary conditions can be easily implemented in FEM.

  • Higher order elements may be implemented.

  • FEM is simple, compact and result-oriented and hence widely popular among engineering community.

Disadvantages:

  • Large amount of data is required as input for the mesh used in terms of nodal connectivity and other parameters depending on the problem.

  • It requires a digital computer and fairly extensive

  • It requires longer execution time compared with FEM.

  • Output result will vary considerably.

SOFTWARES:

The global finite element analysis software market has grown exponentially over the years. Innovation in science & technology and engineering and increased investments in research and development by companies worldwide have played a key role in such spectacular market growth. According to an August 2022 report by Research Nester, revenue generated by the FEA software market stood at $5 billion in 2021, which is expected to climb to $12 billion by 2031, expanding at a CAGR of around 10%. Moreover, as per the report, ANSYS, Inc., Synopsys, Inc., Autodesk, Inc., Dassault Systems, and IBM Corporation are key players in the FEA software market.

Let’s look at some of the top finite element analysis software


1. ANSYS

ANSYS is a popular FEA software that is extensively used in the engineering space. The software embeds several modules capable of simulating various physical aspects such as fluids (in CFX and FLUENT), static/dynamic motion analyses, thermal/structural analyses, and modal analyses for determining vibrational frequencies. ANSYS FLUENT works with 2D mesh, while CFX uses tetra and mesh structures (3D). All these modules are combined under the ANSYS framework, offering a comprehensive toolset to study multiple physical factors. Today, ANSYS uses ML methods for dynamically determining simulation parameters. Such practices contribute immensely to speeding up the product design optimization process by analyzing thousands of parameters in no time. As a result, companies see a boost in their business intelligence strategies as it tends to improve the speed and accuracy of product design.


2. SimScale

SimScale is a cloud-based FEA software that serves as an alternative to ANSYS. It consists of three essential modules for thermal analyses, computational fluid dynamics (CFD), and mechanical analyses, such as static/dynamic analyses, vibrational analyses, etc.

Researchers around the world use SimScale to study various complex physical systems. This includes the analysis of planetary mergers or even factors that influence climate on the Earth. The software generates high-quality maps and topographical illustrations, making it suitable for geological research and climate modeling.


3. Autodesk

Autodesk is a well-known engineering software, primarily because of its two units: AutoCAD and Inventor software. Autodesk is computer-aided design software widely used to create 2D and 3D drawings. Autodesk Inventor is a design application used to create 3D mechanical designs, perform simulations, and visualize and document tasks. Autodesk also offers a CFD module for fluid system analyses.


4. ABAQUS


ABAQUS is a competitor of ANSYS software. It provides five specific tools for its users: Complete Abaqus Environment (CAE) for mechanical units and assemblies, Abaqus Standard for static/low-speed dynamic stresses, Abaqus Explicit for non-linear and transient FEA analysis such as automotive crashworthiness, Abaqus CFD for fluid analyses, and Abaqus Electromagnetics, which is well-suited for electronic and electromagnetic studies.


5. OpenFOAM

OpenFOAM is a finite element analysis software that offers cost-effective methods to design, test, and fabricate mechanical & electronic systems. The software is typically designed to maximize the performance of systems operating in the oil & gas industry. It is used by engineers, chemists, and oil & gas commission (OGC) consultants for better decision-making.



Takeaway:


Finite element analysis provides engineers, manufacturers, and designers with multiple ways to speed up their core operations and simplify their workers’ day-to-day jobs. FEA is vital for industries as it cuts down on design and manufacturing costs, speeds up design processes, optimizes designs by evaluating alternative material designs, and reduces unnecessary material waste. Whether in the automotive, manufacturing, aerospace, or energy sector, finite element analysis provides safe, sturdy, and durable designs FEA is predictive but not affirmative.


It doesn't ascertain that a design will repel the simulated stresses with certainty. It only gives masterminds a view of how the design may reply to the assessed stresses while cutting on the cost of physical testing.



"Thanks for reading, please leave a comment :)"


Authors:

  1. Jaydeep Patil
  2. Rohit Patil
  3. Gokarna Lele
  4. Abhishek Kumbhar
  5. Rohit Bele








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