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| report:dvp [2026/05/20 10:48] – [7.6 Tests & Results] team5 | report:dvp [2026/05/28 10:05] (current) – [7.4 Design] team5 |
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| </table> | </table> |
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| <color #ed1c24>Describe and present here the load and stress analysis of the structure (3D model) using the materials chosen for the product.</color> | **Structural Stress and Robustness Analysis** |
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| | To guarantee the physical integrity of the distributed hardware infrastructure and validate compliance with strict public transit conditions, Finite Element Analysis (FEA) linear static simulations were conducted within SimScale. The analysis targeted the specific configurations of the ideal deployment, evaluating the mechanical behavior of both the ceiling-mounted Main Box and the vertical pole-mounted Secondary Node under operational stress and anti-vandalism scenarios (such as passenger impacts or sudden handrail load shifts). Both enclosures were modeled using the properties of the specialized Nanovia PA Rail (Polyamide) compound specified in Table {{ref>components_ideal}}. |
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| | For the ceiling-mounted Main Box, mechanical fixtures (Fixed Support) were applied directly to the internal cylindrical surfaces of the mounting bolt holes, replicating a rigid steel-fastened connection to the carriage ceiling framework. A distributed static structural load of 100 N was applied perpendicular to the lower face of the enclosure, simulating the mechanical force transmitted through the central support pole when handled by passengers. |
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| | As displayed in the optimized Von Mises stress plots for the Main Box (see Figure {{ref>fig:fea_main_interior}} and Figure {{ref>fig:fea_main_exterior}}), the visualization scale was tightly bounded to a maximum of 2.0 MPa ($2.0 \times 10^6\text{ Pa}$) to map the precise path of stress propagation across the enclosure's geometry. The structural tension smoothly gradients from the safe, low-stress outer walls (blue zones) and securely concentrates around the anchoring junctions and sharp internal mounting features (green to red zones). Even with the absolute peak localized stress reaching 3.99 MPa ($3.993 \times 10^6\text{ Pa}$) at the sharpest geometric interfaces, the entire infrastructure operates significantly below the yield strength threshold of industrial Polyamide (which typically spans between 50 MPa and 70 MPa), yielding an exceptional safety factor greater than 12.0. |
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| | <WRAP centeralign> |
| | <figure fig:fea_main_interior> |
| | {{ :report:main_box_front.png?direct&800 | FEA Main Box Internal Stress Map}} |
| | <caption>Top View of Von Mises stress distribution on the main ceiling-mounted PA Rail housing under a 100 N distributed load</caption> |
| | </figure> |
| | </WRAP> |
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| | <WRAP centeralign> |
| | <figure fig:fea_main_exterior> |
| | {{ :report:main_box_down.png?direct&800 | FEA Main Box External Stress Map}} |
| | <caption>Bottom view of the main housing Von Mises stress distribution around the central pole interface junction</caption> |
| | </figure> |
| | </WRAP> |
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| | Simultaneously, the pole-mounted Secondary Node enclosure was subjected to an identical validation process to evaluate its resistance to direct side impacts and handling stress. Fixed support constraints were allocated to its interior hardware mounting bosses, while a 100 N impact-equivalent load was distributed across its interactive face shell. |
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| | As shown in Figure {{ref>fig:fea_secondary_exterior}} and Figure {{ref>fig:fea_secondary_interior}}, the stress distribution follows a highly stable path. Due to the smoothed filleted edges of the enclosure, stress accumulation is minimized, with minor localized concentrations rising around the rectangular cutouts and transitional fillets, reaching a maximum value of approximately 1.60 MPa ($1.6 \times 10^6\text{ Pa}$). This configuration leaves the internal electronic component mounts completely isolated from external physical strain. Operating with an implied safety factor exceeding 30.0 against the material's elastic limit, the secondary enclosure demonstrates outstanding structural resilience. |
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| | <WRAP centeralign> |
| | <figure fig:fea_secondary_exterior> |
| | {{ :report:pole_box_down.png?direct&800 | FEA Secondary Node Exterior Stress Map}} |
| | <caption>Bottom View with Von Mises stress distribution on the pole-mounted secondary node showing stress paths around geometric features</caption> |
| | </figure> |
| | </WRAP> |
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| | <WRAP centeralign> |
| | <figure fig:fea_secondary_interior> |
| | {{ :report:pole_box_front.png?direct&800 | FEA Secondary Node Interior Stress Map}} |
| | <caption>Top view of the secondary node simulation highlighting the stress isolation achieved inside the electronic casing compartment</caption> |
| | </figure> |
| | </WRAP> |
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| | The combined mathematical results from these FEA studies definitively validate the housing architectures against intense public interaction, deliberate vandalism, and the continuous mechanical vibrations typical of the Porto Metro transport ecosystem, proving that no further geometric optimisations are required before prototyping phases. |
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| </WRAP> | </WRAP> |
| </table> | </table> |
| The following images show the physical prototype assembly: | The following images show the design for the planned physical prototype. |
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| PUT PICS OF PROTOTYPE | |
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| == 7.5.2 Hardware == | == 7.5.2 Hardware == |
| **Unit testing**\\ | **Unit testing**\\ |
| The API route handler for /api/messages was tested using Jest. The test suite covers both the GET and POST endpoints, with five test cases: returning a random message when data exists, returning null when no messages are stored, returning HTTP 500 on a Supabase error, returning the AI filter response on a successful POST, and returning HTTP 500 when the fetch call throws an error. All five tests passed in 0.277 seconds, as shown in Figure 33, which confirms that the route logic handles both normal use and error conditions as expected. | The API route handler for /api/messages was tested using Jest. The test suite covers both the GET and POST endpoints, with five test cases: returning a random message when data exists, returning null when no messages are stored, returning HTTP 500 on a Supabase error, returning the AI filter response on a successful POST, and returning HTTP 500 when the fetch call throws an error. All five tests passed in 0.277 seconds, as shown in Figure 33, which confirms that the route logic handles both normal use and error conditions as expected. |
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| <WRAP centeralign> | <WRAP centeralign> |
| <figure fig:jest-test> | <figure fig:jest-test> |
| {{ :report:jest-test.png | Figure 33: test results in terminal}} | {{ :report:jest-test.png?800 | Figure 33: test results in terminal}} |
| <caption>Test results in terminal</caption> | <caption>Test results in terminal</caption> |
| </figure> | </figure> |