Hi Morteza Moradi ,

There are some really good research papers that you can look at for your question. Some of them are listed below

If you like the answer please do make a recommendation so that my research will be more visible. Thank you for asking the question...

Dear Sourangshu Ghosh ,

First, I appreciate your response.

There are some factors which should be considered:

1- the difference of contact properties between composite materials and others like metals.

2- the thermal variation resulted from the vibration of two contact surfaces is the question's purpose here, not the effect of temperature on vibration behavior.

Hence, it seems that only the 3rd suggestion by you is helpful.

Thanks,

Bests,

Morteza

Dear Morteza Moradi,

Bolted joints’ clamp load may also decrease gradually when being subjected to cyclically temperature variation, and it should seem as loosening as well. The temperature variation decreased the bearing and thread friction torque components, which could lead bolted joint to loosen.

What I understand here, with the temperature cyclically changing, if there is a mismatch between the thermal expansions of the bolt and joint, expansion may induce radial shear stress can weaken the friction torques and finally causes bolted joints to loosen. For bolt joints with certain structure parameters, the value of temperature variation that can produce slippage in the first segment of temperature changing is in direct proportion with preload. The amplitude of temperature changing which can induce loosening is at least twice duration of the value. The higher the preload and friction coefficient are, the more slowly the bolted joints may loosen. With the increasing of the contact area, ultimately the contact pressure becomes lower, and the maximum friction torque after heating (or cooling) will be likely less. And hence, the joint with bigger thread clearance and less engaged threads might have higher contact pressure which may causes loosens more slowly. The shear stress components caused by expansion difference, as well as the bearing and thread friction torque components, which depended on the temperature variation.

Ashish