## 5 Results
### Final Swingarm Design Results  
An identical modelling process is followed for the new materials applied, as in the initial design. Only the worst-case scenario (second loading scenario) is used for the evaluation and comparison to the initial version. The forces applied are again \(N_{f}=1210\) N and \(M_{br}=400.5\) Nm and the results of stresses and displacements are presented in Figure 14.  
The maximum stress calculated on the swingarm has a magnitude of 117.2 MPa, resulting in a safety factor \(N=1.95\) (yield strength is 228 MPa). As expected, maximum stress is once more observed on one of the constrained points that connects the swingarm to the chassis, as was the case in the simulation results of the first design. It must be also noted that stress distribution on the rest of the swingarm is below 70 MPa. The maximum displacement results in a value of 1.59 mm. Even though there are no comparative results for front swingarms on the literature, these displacements under heavy braking conditions are evaluated as acceptable. That means that no driving or handling problems would be noticed by the driver in braking conditions. A comparison of results from the simulations conducted for the initial and final swingarm design, can be found in Table 6, including maximum stresses, displacements, weight and safety factor.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **Aluminum** & **Stainless Steel** & **Steel** & **Stainless Steel** \\  & **5083-H116** & **AISI 304** & **AISI 4130** & **A4-80** \\ \hline
**Elastic modulus, E(GPa)** & 71 & 200 & 205 & 193 \\
**Poisson ratio, v** & 0.33 & 0.29 & 0.29 & 0.29 \\
**Shear modulus, G(GPa)** & 26.4 & 86 & 80 & 86 \\
**Density, \(\rho\) (\(\times 10^{3}\) kg/m\({}^{3}\))** & 2.66 & 8 & 7.85 & 8 \\
**Yield strength (MPa)** & 228 & 215 & 435 & 600 \\ \hline \hline \end{tabular}
\end{table}
Table 5: Materials properties used in the final modelling.  
Figure 14: Stress (**a**) and displacement (**b**) results in 2 nd loading scenario for the final swingarm design.  
As shown, the maximum stresses are 19% higher in the final design, as also displacements are raised by 25%. These results were expected but at the same time do not raise any concerns, since they are lower than the material yield strength. Safety factor is reduced, which is normal for this kind of structure and ensures structural rigidity safety levels. The main target was of course to lower weight, which is accomplished, considering that a 23.2% reduction was achieved. Finally, the change of materials decided had minimum overall effects on our results, but on the other hand will help the most on reducing production costs.  
The development procedure presented and decisions taken towards the final design, were based on finite element analysis simulations that were modeled based on our knowledge and experience. Due to the lack of relevant research on front single-sided swingarms, no real comparison can be made to similar research or tests in order to validate our results. One engineering parameter found from rear swingarm analysis (as referred to in Table 2 and used for validation in our case), is the safety factor. In rear swingarms it ranges from 1.53 to 2.39 with a mean value of 1.95, which is an important parameter that we successfully met on our new design. The next step would be to set up an experimental testing procedure on a custom test rig, which would provide additional strain and displacement data for the validation and tuning of our finite element model. We should also mention that since the suspension and tire effects are not considered in our model, the results of stresses and displacements are higher, providing additional certainty that we can further reduce the weight. According to the above, we are confident that the proposed design will provide the needed safety during driving and braking.