Data Entry Clerk - Go Kart Frame Design - Finite Element Analysis (FEA) Of a Go Kart For Maximized Strength

The Finite Element Analysis (FEA) was chosen to maximize the strength of the frame in question and minimize weight. Abstract: Go Kart Frame of square tubing design had questionable tube placement and section issues.

Frame Under Consideration: Gamblighini Phi-Alpha 10 with no roll cage.

Loading Considerations:

- Twisting Load
- Bump Load

Weight of Frame: 300 lbs

Weight of person 200 lbs

070 wall to see effects. 109 (12 GA) stepping down to . Initial sectional properties: 1 x 1 inch .

000 psi yield material Properties: ASTM A-36: 36,

Introduction to Finite Element Analysis (FEA)

The amount of deflection the element will produce, stress being the amount of load the particular element can handle and strain. The load effects are stress and strain. Finite Element Analysis (FEA) is a program that places many small "elements" on the model in question and then calculates the load effects on the element.

The computer can crunch through millions of calculations in a matter of minutes, instead of doing it all by hand, fEA is a fantastic tool for crunching down the complex into the simple. High powered computers are needed to crank through the mathematical nightmare efficiently, however even then, fEA can be conducted by hand using Matrix Math.

What we are looking to do on this frame is to maximize the strength and minimize the weight.

There are several ways to run the analysis on this frame: as an introduction,

-Solid Model
-Shell Model
-Truss Element Model

Solid Modeling

So typically "mental gymnastics" has to be performed to reduce the model size and allow it to be computed without using so much computer brain power. Up towards the millions and would actually be very difficult to run even in a very high powered computer, the model will have many element. The solid model require high powered CAD software to begin with that draws the model in 3-D and as "real life" tube structures.

And reduce the amount of passes the computer must make to calculate, reduce the number of elements, then the best route is to either cut the frame in half, if you are guessing as to what the frame is going to handle initially and have no idea where the stresses are going to show up. The ideal is to reduce the high stress areas into chunks that can be managed, for those who are going the route of solid modeling.

Typically two passes is enough to get a close answer. Subsequent passes get closer gradually. The second calculation recalibrates and gets a lot closer, the first calculation is trying to get you into the general area of the bull's-eye. It uses high level math (ie Calculus on steroids) and actually is like shooting an arrow at a target, for all those new to FEA.

If using solids, that is what FEA demands of a computer. 000 equations all at one time, so imagine the computer cranking through 100.

Shell Modeling

The assumption of the shell modeling software can be deceiving. The problems though are joining shells together. The nice thing about shells is that it uses less brain power and can actually give you an answer that is just as good as a solid model. Shells take a tube and assume it to be as thin as paper (in its representation) then it slaps on to the cross section the thickness and the moment of inertia values (I). The second method is shells.

Resort to solids at the higher stress sections, if a higher result is needed. Solids can yield a better result, with that in mind. And the weld itself may or may not be large enough at the intersection, you and I know that the tube only gets partial penetration. The intersection point is assumed to be completely welded across the whole boundary of the tube. Example: A square tube welded to a square tube sideways.

Truss Modeling

A typical program can cost less than $1000, and to make things even better. A truss model can be slapped together in about 10 minutes and results attained using a low powered computer. This is the lowest HP solution of them all and yield good results as well. The third method is the truss calculation method.

So next time we will show how to put the go kart frame on a FEA program using truss modeling. And will be calculated using the truss method, the overall frame design has been introduced into the FEA software as a wireframe.