# FEA Analysis

# Finite Element Analysis of Motor Mounts

In total there was two fea analysis done, one on the mounts that hold the thruster in place an attached by epoxy, Anne one that analyzed the entire structure as a worst-case scenario. Beginning with the analysis of the ABS motor Mount we would like to make sure that it will hold during normal operating procedures.

Since the model for this fea analysis is in inches The US unit inch quantities will be used. The maximum thrust force on any of the thrusters is five kilograms, so when we multiply that by gravity, we come out to roughly fifty newtons which are also roughly eleven pounds of force. Dividing that by the curved surface area of the components, a shear force is calculated. The epoxy shear strength and ABS strength will be analyzed in Abaqus. The first step was to constrain the side attached to the hull of the UUV fixed. Then a surface shear force of about eleven pounds of force is applied the results will be in psi.

## ROVfra008 FEA model

## ROVfra009 FEA model

# Full Body FEA Analysis Positive Heave

Next to the whole-body simulations, it is important to note that the maximum case was analyzed. The factor of safety was expected to be extremely high due to the low force on the system. Five cases were analyzed, diving, surfacing, forward surge, reverse surge, and yaw right. There were a couple of assumptions.

1. All connections were global bonded connections.

2. Roller constraints on faces that oppose the direction of force, to simulate the worst-case scenario.

3. The mesh was midway between coarse and fine.

4. The parts were galvanized steel, PVC rigid, and 3D printing ABS.

5. The force was eleven pounds of force as a shear force, which was previously discussed.

## Von Mises

## Displacement

# Full Body FEA Analysis Negative Heave

The meshing for the positive and negative heave was very similar, so only the displacement and results will be shown here.

# Full Body FEA Analysis Positive Heave

The simulation results for a positive heave FEA analysis.

## Von Mises

## Displacement

# Full Body FEA Analysis Negative Heave

Since the meshing, von mises, and displacements were very similar to the above case, the meshing will not be shown.

## Von Mises

## Displacements

# Full Body FEA Analysis Yaw Spin

The last case analyzed was the yaw spin. This was analyzed by putting a five kilogram of thrust force facing against each other on different sides of the thrusters.