| Abstract Scope |
A failure analysis was conducted on a failed garage door torsion spring. Garage door springs use torque to counterbalance garage doors’ weight for easy opening and closing. The spring winds up to keep the door closed and unwinds to lift the door. The cause of failure for the garage door spring was investigated through macro/micro imaging, along with taking hardness and chemistry of the sample. It was found that the sample adhered to ASTM A229 specifications for hardness values and maximum depth of decarburization with microhardness testing and optical microscopy. No lubrication was observed on the spring, which is believed to have caused wear marks on the spring surface. By investigation with a scanning electron microscope (SEM), it was found that the spring’s fracture most likely initiated by fatigue and progressed as a tensile ductile fracture. To alleviate excess stress concentrations, it is recommended that the spring be lubricated. |