Research On Safety Early Warning Of Machinery & Electrical Products

With the development of science and technology, machinery & electrical products have played an important role in our life. Also, the poor product safety which led to casualties and property losses are a common occurrence. As one of the key character parameters of product, this paper introduces the concept of early warning to improve the safety for products, which is a effective method to reduce unnecessary casualties, property losses etc.Machinery & electrical products safety early warning model is based on the system safety & security analysis methods and failure probability theories. It aims to make a failure probability relationship between products and its parts, and then calculate a time value, in which failure probability of occurrence reach unacceptable. First of all, according to Severity grade of unexpected mishaps define early warning levels. Second, set a foregone ultimate value of failure probability of unexpected mishaps on the basis of experiences or the relevant standards etc., by the FTA to identify failure parts (The Minimal Cut Sets) which cause unacceptable mishap happened. Using Weibull failure probability distribution function set failure probability of parts. At last, carry the probability formulas of the occurrence mishaps in the FTA combine with failure probability formulas of parts, and then make equations which contains the parameter of time, the solving results are the early warning time, so that, this can prevent mishap happened.For repairable products, the second early warning is proposed, when the repairable products after repaired can apply early warning to improve safety also. In the last chapter of this thesis, we illustrated this model with the example of elevators.