This study is to deal with a failure phenomenon that occurred during a vibration test on an Inertial Navigation System mounted on a self-propelled howitzer. Vibration occurs naturally due to the operation characteristics of self-propelled howitzers, The study describes a case of failure that occurred during the durability verification process. It explains the function and configuration of the INS(Inertial Navigation System) and describe how the failure occurred through understanding the phenomenon. Based on the occurrence phenomenon, an in-depth cause analysis was conducted and fundamental improvement measures were presented to prevent recurrence. It is expected that this study will aid as a reference for problem solving when similar failures occur in the future.

In this study, analyzed the cause of failure of the cardan shaft for water propulsion of an armored wheeled vehicle. During the development test(DT), the vehicle was deflected to the left on the water. As a result of the confirmation, increasing angular displacement and abrasion of SPIDER(Universal joint) occurred. As a result of a structure analysis and torsion fracture test, cause of failure is not insufficient design and strength deficit of each parts. and as a result of a simulation review of the assembly layout of each part, it was confirmed that excessive rotational vibration occurred. In order to solve this problem, improved the assembly layout of the water propulsion system and the worn SPIDER lubrication. Since there has been no occurrence of the same case between military operations so far, it has been confirmed that the improvement plan is appropriate.