Assessment of product stability

Abstract

In this paper the mechanical stability of consumer products is discussed from both a theoretical and a practical point of view. It is shown that the two methods of stability testing most often used in product safety standards (inclined plane and destabilizing force) can be used for determining a third important parameter, the overturning energy. Furthermore, test results for a broad range of products are presented in terms of the three parameters tilt angle, destabilizing moment and overturning energy. In existing and currently proposed draft standards a variety of test procedures and, more important, criteria for stability can be found. The level of safety is not clear and cannot be compared between various products. Therefore, a new and more consistent approach is proposed for developing stability requirements in standards: instead of a pass/fail criterion a risk assessment procedure can be followed in which the test results are compared with the foreseeable external influences (moving person, pushing, etc.) taking into account the risk of injury in case of overturning. The new approach is applied as an example to one of the tested product types.