To determine the deformation behavior of metallic materials during forming processes with dominant bending elements or during crash loading, the 3-point flexure test kit from ZwickRoell was newly developed in collaboration with a large automobile manufacturer from the south of Germany. As a beta customer, the company tested the 3-point flexure test kit and further developed it with ZwickRoell. The highlight of the progression was the development of a camera system / optical system for determination of the bending angle as well as crack image capturing. Very high stiffness of the test tool was also achieved, completely fulfilling VDA238-100:2017 requirements.
The VDA 238-100:2017-06 is the basis for the test arrangement. This 3-point flexure test kit is used to perform small plate bending tests for determination of the bending angle with the goal of reaching conclusions on the deformation behavior of metal materials during forming processes with dominant bending elements (e.g. hemming operations) or during crash loading.
With the test fixture from ZwickRoell, all three methods of the VDA 238-100:2017-06 are available for the test evaluation:
- Annex C: Manual measurement of the bending angle using a protractor after the measurement
- Annex D: Software assisted calculation via crosshead movement
- Annex E: Optical measurement via high-precision camera system with additional measurement of the elastic deformation during load application on the specimen
- High stiffness: with a punch force of 3000 N, the maximum total widening of the rollers is 0.1 mm
- Support rollers:
- Distance can be set steplessly from 0 to 15 mm
- Position securement via manually operated hydraulic clamp (included in scope of delivery)
- Anvil rollers, bearing mounted and surface hardened
- Maximum test force Fmax 20 kN
- For specimen thicknesses up to 7 mm
- A test evaluation to Annex E of the VDA 238-100:2017-06 is only possible with a bending angle camera. ZwickRoell thereby enables the evaluation according to all three types of determination of the bending angle (Annex C, D and E).
- Automatic measurement of the elastic and plastic portion of the bending angle saves time and reduces operator influence when compared to conventional manual processes.
- Operator influence is reduced to a minimum by using optical roller distance measurement. Measurement value transmission to testXpert documents the roller distance and ensures traceable test results.
- The correlation between force, bending angle and crack pattern can be viewed in testXpert at any time during the test, allowing for detailed analysis of the material failure. This is implemented by synchronous optical recording of the crack pattern, the bending angle and the force.
- Mounting of specimen grips and test tools without removing the test fixture by using adapters.
- Attachment points for ring bolts for use with lifting devices when mounting the 3-point flexure test kit in the testing machine.
|Type||3-point flexure test kit|
|Test load Fmax||20||kN|
|Height without connection||85||mm|
|Radius||0.2 and 0.4||mm|
|Width||30 ... 60||mm|
|Support roller distance, stepless||0 ... 15||mm|
|Anvil span, stepless||30 ... 45||mm|
|Connection, upper||Mounting stud Ø 16 mm|
|Connection, lower||Pitch circle Ø 220 mm (2 x M16x35)|
|Ambient temperature||+10 ... +35||°C|
|Type||Hyspin XP 46|