BEND TEST FOR SHEAR STUDS

Introduction

This tutorial provides a comprehensive guide on conducting a bend test for shear studs, a critical procedure in evaluating the quality of welded fasteners. By following these steps, you'll learn how to effectively assess the ductility and soundness of welds in mild steel and stainless steel applications, ensuring the integrity of your welding processes.

Step 1: Understand the Bend Test Fundamentals

• The bend test is a qualitative procedure that evaluates the weld’s ductility and soundness.
• It involves bending welded specimens to check for defects such as cracks or discontinuities.
• The test should be performed using specimens cut from a single weld plate, typically ranging from 6x6 inches to 8x24 inches.

Step 2: Prepare the Specimen

• Cut the specimen from the welded plate according to specified dimensions.
• Ensure the specimen is free from any visible defects before testing.
• Identify the area of the weld that will be subjected to bending to focus on potential imperfections.

Step 3: Conduct the Bend Test

Method 1: Bending with Drawn Arc Stud Welding

1. Setup: Position the specimen securely.
2. Angle: Bend the studs through a 60° angle using drawn arc stud welding with a ceramic ferrule or shielding gas.
3. Observation: Visually inspect the bent area for any cracks, orange peeling, or other defects.

Method 2: Bending with Capacitor Discharge Stud Welding

1. Setup: Position the specimen securely.
2. Angle: Bend the studs through a 30° angle using capacitor discharge stud welding with tip ignition.
3. Observation: As with the first method, check the bent area for defects.

Step 4: Apply Bending Moment Below Elastic Limit

• Stress the studs by applying a bending moment that does not exceed the elastic limit.
• Use a hammer or pipe to bend the studs, ensuring to maintain control over the bending process.
• For deformed bar anchors, bend around a pin with a diameter equal to twice that of the specimen.

Step 5: Inspect and Document the Results

• After bending, visually inspect the specimen for any defects.
• Take note of any issues such as cracks or discontinuities and document them in the test report.
• If defects are found, adjust the welding settings and repeat the test.

Conclusion

The bend test for shear studs is an essential procedure for evaluating the quality of welded connections. By following these steps, you ensure that your welding practices meet industry standards and that the welds maintain their structural integrity. After successful testing, you can confidently proceed with production, knowing that your welds have passed the necessary evaluations.