STRUCTURAL ANALYSIS AND

OPTIMIZATION ON COM–

PONENTS OF KNUCKLE JOIN

Anu Nair Krishnaswamy Mahadevan

Robinpreet Dhillon

Faculty Mentor: Eduardo Chan, PhD

Project Sponsors: ANSYS,Inc

Abstract

Knuckle joint is a type of mechanical joint used in structures, to connect two intersecting cylindrical

rods, whose axis lie on the same plane. It permits some angular movement between the cylindrical

rods. It is specially designed to withstand tensile loads. In this project, we have designed two major

components of knuckle joint in ANSYS WORKBENCH and statically analyzed by applying tensile

loads in the direction of rod end. In this project we have also done shape optimization in ANSYS

WORKBENCH with the objective to reduce weight.

Knuckle Joint Assembly

Introduction

In this project we have structurally analyzed and

optimized two major parts of knuckle joint: Fork end

and Eye end. The main objective is to reduce the mass

and total deformation of both components for various

parameters to get better design criteria.

A typical knuckle joint has the following parts:

1. Fork end

2. Eye end

3. Knuckle pin

4. Collar

5. Taper pin

Exploded view of Knuckle joi

Pre-optimization

Following Material was selected for this project:

Meshing of Eye end and Fork end was done by using Face Sizing and Relevance Factor on parts where we

expected higher deformation.

Eye end Fork end

Relevance 100 100

Relevance Center Fine Fine

Face Sizing 0.5 mm 0.5 mm

Average Element quality 0.8 0.77

Average Aspect Ration 1.9 2

Average Skewness 0.29 0.33

Generated mesh

Eye end

Fork end

Boundary conditions

Fixed Support Pin end (where pin is being

inserted)

Pin end (where pin is being

inserted)

Load 30,000 N 30,000 N

Analytical Calculations

D = √4𝑃

𝜋[𝜎]

30 𝑚𝑚 = √4 ×30000

𝜋×[𝜎]

[𝜎 ] = 43 N/𝑚𝑚2

[𝜎] = 𝑆𝑦𝑡

𝐹𝑂𝑆

43N/𝑚𝑚2 = 400

𝐹𝑂𝑆

FOS= 9.3

D= Diameter of the rod

[𝜎] = Permissible stress

P = Applied force

𝑆𝑦𝑡= yield stress of material

FOS =factor of safety

Pre-Optimization Results

Total deformation Total deformation

Von mises stress Von mises stress

Proposed Shape Optimization

Eye End Fork End

The above images shows the shape optimization results for the eye end and fork end

Post-optimization

Fork End Response Surfaces

Eye End Response Surfaces

Optimized Total Deformation Optimized Total Deformation

Optimized Von Mises Stresses Optimized Von Mises Stresses

Conclusion

Fork end results after Optimization Eye end results after Optimization

The above tables summarize the final optimization results of Fork end and Eye end.

Team was successfully able to reduce mass and deformation of fork end and eye end in ANSYS Workbench

software. We have found out that mass reduces by 1.2% for fork end and 1.05% for eye end. The change in mass

and total deformation is achieved by altering edge fillet radius and square radius for eye end and fork end.

Before After

Edges (All4) 3 mm 6.3mm

Square Radius 2 mm 5 mm

Filleted Radius 2 mm 5 mm

Total Deformation 0.018648 mm 0.01857 mm

Mass 1.394 kg 1.325 kg

Before After

R2 59.5 mm 56 mm

Edge (All 4) 3 mm 7 mm

Total Deformation 0.024587mm 0.024254 mm

Mass 2.42 kg 2.38 kg