Tiller Strut Analysis

The previous design for the Tiller Strut is analyzed as a rigid body with fixed support and loads applied to represent the external forces acting on the system. Tiller Strut is composed of Aluminum 6061-T6.

The Tiller Strut is analyzed through ANSYS Workbench:

The model was directly imported from SolidWorks to represent the previous system design.

Model was meshed with .25” size elements uniformly across the entire system.

Fixed supports are applied to the points were the bolted connection would be located. A line loads are applied at strategic points on the Tiller Strut to represent where that force

would be exerted on the system. Load is applied to system to represent the mechanical advantage given through the system. The

two cases include the previous load from the previous design and the enhanced load from the updated design and oriented to simulate the boat going straight. The line load on the top bar is assumed to be applied at 30 degrees to connect to the tiller arm. The previous design load was 85lb on the tiller strut and the enhanced load in 150lb for the new system.

o Case #1: Previous load of 85lb on previous design.

o Case #2: Enhanced load of 150lb on previous design.

Deformation in the different cases was found to be:o Case #1: Deformation = 0.353in

o Case #2: Deformation = 0.622in

Von Misses stress in the different cases was found to be:o Case #1: Peak Stress: 39157Psi

o Case #2: Peak Stress: 69102Psi

Factor safety in the different cases using the Yield stress of Aluminum 6061-T6 was found to be:o Case #1: Lowest Factor of Safety = 1.04

o Case #2: Lowest Factor of Safety = 0.59

Conclusion

The Tiller Strut is made of Aluminum 6061-T6 and is being treated as a rigid body during the course of these calculations. By the analysis done through ANSYS Workbench with the two loading cases, the results and calculations show that the previous design for the tiller struts would not be able to withstand the enhanced load from the new system and will likely yield under loading at peak loading conditions. It must be noted that the factor of safety calculated is based on calculations done through distortion energy where the solver utilizes the von misses stress against a material’s yield stress to solve for FOS.

Load (lb) Deformation (in)

Peak Von Misses Stress (Psi)

Minimum F.O.S. in Crank

Case #1 (Previous Load)

85 0.353 39157 1.04

Case #2 (Enhanced Load)

150 0.622 69102 0.59

Final conclusion is that the Tiller Strut will not be able to withstand the Enhanced load of 150lb generated through mechanical advantage of the new proposed design. Steps must be taken to redesign the Tiller Strut as well to withstand the new load generated in the new design. It must be noted that these simulations and calculations do not account for material or manufacturing deformities that may cause stress concentrations to appear in unspecified locations and lead to premature failure of the part.

Tiller Strut Redesign Analysis

A new design for the Tiller Strut is analyzed as a rigid body with fixed support and loads applied to represent the external forces acting on the system. Tiller Strut is composed of Aluminum 6061-T6. The new design became necessary as the previous design was unable to withstand the enhanced load of the new system. Thus, a new design is proposed utilizing square tubes that can withstand greater loads due to it geometry and still maintain a fairly light weight overall.

The Tiller Strut was analyzed through ANSYS Workbench:

The model was directly imported from SolidWorks to represent the new system design.

Model was meshed with .25” size elements uniformly across the entire system.

Fixed supports are applied to the points were the bolted connection would be located. A line loads are applied at strategic points on the Tiller Strut to represent where that force

would be exerted on the system. Load is applied to system to represent the mechanical advantage given through the system. The

three cases include using the enhanced load of 150lb in three different orientations. The first case simulates the boat going straight. The second case simulates the boat turning left. And the third case is the boat going right. No greater load cases are attempted as it is assumed that if any greater load is required to steer the boat the user would not be able to exert it as his threshold is assumed to be 20lb. In such a scenario the emergency override must be engaged by another sailor to steer the boat manually themself who is able to overcome the new loading.

o Case #1: Simulates the boat going straight under peak load.

o Case #2: Simulates the boat turning left under peak load.

o Case #3: Simulates the boat turning Right under peak load.

Deformation in the different cases was found to be:o Case #1: Deformation = 0.06in

o Case #2: Deformation = 0.12in

o Case #3: Deformation = 0.12in

Von Misses stress in the different cases was found to be:o Case #1: Peak Stress: 17378Psi

o Case #2: Peak Stress: 30875Psi

o Case #3: Peak Stress: 29458Psi

Factor safety in the different cases using the Yield stress of Aluminum 6061-T6 was found to be:o Case #1: Lowest Factor of Safety = 2.09

o Case #2: Lowest Factor of Safety = 1.18

o Case #3: Lowest Factor of Safety = 1.23

Conclusion

The Tiller Strut is made of Aluminum 6061-T6 and is being treated as a rigid body during the course of these calculations. By the analysis done through ANSYS Workbench with the three loading cases, the results and calculations show that the new design will be able to withstand the stress without yielding under loading at peak loading conditions. It must be noted that the factor of safety calculated is based on calculations done through distortion energy where the solver utilizes the von misses stress against a material’s yield stress to solve for FOS.

Load (lb) Deformation (in)

Peak Von Misses Stress (Psi)

Minimum F.O.S. in Tiller Strut

Case #1 (Going Straight)

150 0.06 17378 2.09

Case #2 (Turning Left)

150 0.12 30875 1.18

Case #2 (Turning Right)

150 0.12 29458 1.23

Final conclusion is that the new Tiller Strut design will be able to withstand the Enhanced load of 150lb generated through mechanical advantage of the new proposed design. The implementation of the square tubes should also work to limit the deformation caused by the accentuated loading to less than 1/8”. Overall, the new design will be expected to perform well in implementation under ideal conditions. It must be noted that these simulations and calculations do not account for material or manufacturing deformities that may cause stress concentrations to appear in unspecified locations and lead to premature failure of the part.