Dynamic reliability evaluation method for coupling faults of middle trough of scraper conveyor

A dynamic reliability evaluation method for coupling faults of a middle trough of a scraper conveyor, comprising the following steps:

• step 1:
• defining a data collection time point, collecting data samples such as a crack length, a middle plate width, a fracture toughness, a yield strength and a fatigue load of the middle trough of the scraper conveyor at different operation time points, and counting first four moment probability information of each category of the data samples;
• step 2:
• respectively defining performance functions in two failure modes according to fracture failure criteria and static strength failure criteria of the middle trough of the scraper conveyor;
• step 3:
• on a basis of the first four moment probability information of each category of the data samples of the middle trough of the scraper conveyor, building a probability distribution function of each failure mode by using a moment-based saddlepoint approximation method, and calculating failure probabilities of fracture failure mode and static strength failure mode at different time points;
• step 4:
• building a dynamic probability correlation structure between the fracture strength mode and the static strength failure mode of the middle trough of the scraper conveyor by using a dynamic copula function, and further building a dynamic joint probability distribution function between the failure modes;
• and
• step 5:
• performing dynamic reliability evaluation on the coupling faults of the middle trough of the scraper conveyor in combination with the probability distribution function and the dynamic joint probability distribution function of each failure mode of the middle trough of the scraper conveyor and by using a system reliability theory.