¶ Introduction
¶ Purpose, Objective and Scope
Purpose
This document outlines the specifications for a tensile test conducted using a Zwick 100kN testing machine. The primary objective is to determine the tensile strength of the tested material.
Objective
The objective is to verify if the tested material can withstand a maximum tensile force of 100 Mpa without failure. The results will validate the mechanical performance in compliance with ISO 527-2 standards.
Scope
This test focuses on rigid molded plastic samples intended for industrial applications. The tests will be performed following ISO 527-2:2012 methodology.
It is aimed at the person who will be carrying out the mechanical tests and provides the following guidelines.'
It covers the testing protocol as well as the different points of analysis.
The document does not cover the actual analysis of the results neither the tests report.
¶ Applicable and Reference Documents
/competition/firehorn/structure/internal-structure/2025_C_ST_RAIL_BUTTON_FEA
- 2024_C_ST_RRB_DDF
- 2025_C_ST_RAIL_BUTTON_FEA
ISO_527-2:2012_EN- ISO_527-2:2012_FR
Website machine Zwick
¶ Requirements to be verified
¶ Rail Buttons Load Case
- 2024_C_SE_ST_INTERNAL-STRUCTURE_REQ_03 Rail Buttons Load Case
Each rail button shall be able to withstand a force of [4400]N (in the radial direction of the LV).
¶ Test Specification
¶ Open issue, Assumption and Constraint
- Creating 3d prints with PEI filament is very complicated, so the test date may be pushed back even further.
- The structure in which the filament is deposited and the direction in which the machine passes can vary the mechanical properties of the part, making it anisotropic.
- If PEI printing is impossible, we'll have to buy a block and machine it directly.
¶ Test Description
- The purpose of this test is to determine the elastic limit, Young's modulus, its breaking limit and its resistance by observing the tensile curve of PEI samples.
- For this we wish to carry out a test using a tensile machine from the DLL with the software TestXpert II on TWO or THREE samples. We will also need an extensometer and the different components of the machine.
- The values measured directly during a tensile test are the force F and the elongation ΔL, rather than the stresses and the deformation. We can divide by the area S0 to have the constraint.
¶ Test Species
(ISO_ISO_527-2:2012)
| Property | 1A |
|---|---|
| Total length (l₃) | 170 mm |
| Length of narrow section (l₁) | 80 ± 2 mm |
| Radius (r) | 24 ± 1 mm |
| Distance between parallel faces (l₂) | 109.3 ± 3.2 mm |
| Width at ends (b₂) | 20.0 ± 0.2 mm |
| Width of narrow section (b₁) | 10.0 ± 0.2 mm |
| Recommended thickness (h) | 4.0 ± 0.2 mm |
| Gauge length (L₀) | 75.0 ± 0.5 mm |
| Initial jaw separation (L) | 115 ± 1 mm |
¶ Test Requirements
Training for access to the machine and Med 3 room 1523 with Robin Amacher.
Accuracy: ±1% for force and displacement measurements.
Applicable standards: ISO 527-2:2012.
Reserve the room, register in the booklet and follow the machine's instructions.
¶ Test Sequence
Put the machine in Set Up Mode
There's a small book in the room with all the machine's instructions to ensure proper use.
- Step 1: Mounting the specimens in the grips.
- Step 2: Choose the right iso file in the machine
- Step 3: Check the wizzard and validate everything as well as the machine set-ups (and limits)
- Step 4: Set force zero
- Step 5: Start the Test. (In test Mode)
- Step 6: Observing results (failure or deformation).
- Step 7: Compiling and saving the data.
¶ Pass/Fail Criteria
The test is passed if the elastic limit of the 3D printed PEI samples are above 51MPa, which is the maximum stress that can be in the rail button.
¶ Test Procedure
¶ Item Under Test
| Sub-System | Part Name/ID | Type of Part | Version ID |
|---|---|---|---|
| Structure | 000000_id | PEI_Sample | 12.04.24 |
¶ Test Equipment Checklist
| Equipment |
|---|
| Zwick 100kN |
| Extensometre |
| Safety Glasses |
| Traction Grip |
| Logicial TestXpert II |
¶ Test Instrumentation Description
The test instrumentation is a tensile machine from the DLL with the software TestXpert II
Accuracy: ±1% for force and displacement measurements.
¶ Test Location and Conditions
- The subsystems present will be those of structure_rail-button and test.
- The test schould take place in building MED-31523 at EPFL
- Conditions: Ambient temperature (23 ± 2 °C), controlled humidity (50 ± 5%).
¶ Test Safety
Never Manipulate the sample and the machine in Test Mode, always in Set-up mode
- Double Check the strong limite for the machine
- Don't be too close to the machine during test without Safety Glasses
| Safety Concern | Probability | Impact | Severity | Mitigation |
|---|---|---|---|---|
| Sudden specimen failure | Moderate | High | High | Install safety barriers. |
| Misalignment | Low | Medium | Medium | Pre-test inspection. |