Abstract: This paper deals with the design of Optimal Step-Stress Partially Accelerated Degradation Test (PADT) using Wiener Process for modelling degradation paths. In partial step-stress loading, the unit is tested at usual stress for some time and then stress is accelerated. This helps in preventing over-stressing the test specimens. Failure occurs when the performance characteristic crosses...

A reliability-based method for inspection scheduling of steel bridges is proposed to yield the optimal (most economical) inspection strategy that meets an acceptable safety level through the planned service life. Two fatigue reliability formulations that can be applied for most details in steel bridges are presented. For details classified according to AASHTO fatigue categories, a limit state f...

To prevent members in steel bridges from fatigue failure, one usually needs to perform frequent periodic bridge inspections and employ detailed inspection methods. This is especially true for fracture-critical members or details. Carrying out these inspections puts a large burden on a transportation agency’s bridge maintenance budget. A systematic reliability-based method for inspection schedul...

acceptance sampling models have been widely applied in companies for the inspection and testing the raw material as well as the final products. a number of lots of the items are produced in a day in the industries so it may be impossible to inspect/test each item in a lot. the acceptance sampling models only provide the guarantee for the producer and consumer that the items in the lots are acco...

Acceptance Sampling models have been widely applied in companies for the inspection and testing the raw material as well as the final products. A number of lots of the items are produced in a day in the industries so it may be impossible to inspect/test each item in a lot. The acceptance sampling models only provide the guarantee for the producer and consumer that the items in the lots are acco...

Relevant material and environmental parameters are required in modelling chloride ingress into concrete. They could be determined from experimental data (concrete cores taken during inspection) but in practice data availability is limited by time-consuming and expensive tests. Consequently, the main objective of this paper is to develop an approach based on Bayesian networks (BN) to improve the...

We consider a hypothetical company that is assumed to have just manufactured and sold a number of copies of a product. It is known that, with a small probability, the company has committed a manufacturing fault that will require a recall. The company is able to observe the expiration times of the sold items whose distribution depends on whether the fault is present or absent. At the expiration ...

Recently, a step-stress accelerated degradation test (SSADT) plan, in which the stress level is elevated when the degradation value of a product crosses a pre-specified value, was proposed. The times of stress level elevating are random and vary from product to product. In this paper we extend this model to a more economic plan. The proposed extended model has two economical advantages compared...