Development of a Mechanical Shock Test Equipment

Abstract: A simpler version of a shock-testing machine was developed and built. This allows engineers at Verisure to test prototypes and early versions of new products before the product is certified. An independent company shock tests the product as part of the process to certify it as an approved home alarm security product. During the shock test, the product is subjected to a high acceleration during a short time (pulse). The shock shall be a half-sine, 100 g, 6 ms pulse, in accordance with the certification standards [1], [2]. A commercial shock-testing machine was not a suitable option and a simpler version, specifically suited for this case was therefore needed. This report details the steps taken as part of the development process leading up to the construction and testing of the shock-testing equipment. The design choices made throughout relies mainly on physical testing instead of complex FEM simulations in the effort of reaching the end goal of building the test equipment within the thesis’ limited time. The final design is a Free Fall Drop Tower type design with the frame comprised of aluminum profiles and steel rods with linear bearings to guide the motion of the carriage on which the product is mounted. The half-sine pulse shape is generated when the carriage impacts the polyurethane cylinder, called the “programmer”, at the bottom and is measured by an accelerometer mounted on the carriage. All target specifications were met, and the shock testing equipment can produce the needed shock pulse to an acceptable level.