Evaluation of Failure Factors of a Small-Scale Motor in Laboratory Testing

The purpose of this study is to investigate and identify the failure of a small-scale motor in static tests and provide a solution to prevent it. The small-scale motor in this research has four SRM segments that are modeled on the internal ballistics of the shuttle booster motor and the construction of the Arian5 booster. First, a summary of the factors affecting the failure of solid rocket motors is presented, and then, the small-scale motor design and its prediction of ballistic performance are discussed. Following is the success of the first test and the failure of the second and third tests of the motor and its results. In order to evaluate the causes of second and third motor failure in static testing, the possible causes of the motor failure phenomenon are discussed, and finally, the main cause of motor failure is identified. The most common cause of failure in this project was the human error in defining the assembly of the throat parts and due to the closure of the combustion path.