The purpose of a joint study is to understand the forces acting on the assembly during tightening. A joint study may be necessary if you have a critical joint or if you are having warranty claims that can be linked back to joint failure. When is a joint considered critical? If the failure of the joint may cause injury or have a serious monetary impact, it should be considered critical.
Typical Types of Joint Studies
1.Torque Tension Analysis
This study is used to make sure that your prescribed torque is achieving your intended clamp load. Low clamp load may lead to loosening through embedment, rotational loosening and/or fatigue which all can result in failure of the joint. High clamp load may yield the fasteners or the mating joint components, lowering their clamping force which can also result in failure of the joint.
2.Drive & Strip Torque Analysis for Thread Forming Screws
Performance of thread forming screws in both metal and plastic are greatly dependent on the hole size and preparation. The correct hole size should offer a good balance between low drive torque and high strip torque which can be determined through testing. These types of joints aren’t often as sensitive to the amount of clamp load they retain, but choosing the proper hole size and assembly torque will greatly affect the joint’s performance.
3.Vibration Analysis
Joints subjected to vibrational forces may experience loosening and eventual failure if not designed properly. Different types of fasteners and locking features are often utilized to address vibrational loosening. Performing a vibration study helps to select the proper hardware for your specific situation.
To learn more about joint studies and to talk to an engineer about your project, contact us through ProvenProductivity@bossard.com.
Doug Jones
Applications Engineer
djones@bossard.com
