Jaroslav Menčík

By Jaroslav Menčík

Part of the book: Nanoindentation in Materials Science

By Jaroslav Menčík

Part of the book: Concise Reliability for Engineers

By Jaroslav Menčík

Failure Mode and Effect Analysis (FMEA) is a simple procedure for systematic revealing of possible failures of structures or processes as early as in the design stage. The main steps of this procedure are explained. Classification of severity, frequency and possibility of early detection of the individual failure modes is shown, as well as the calculation of the risk priority number, which serves for finding the most dangerous causes of failures. The application of FMEA is shown on an example.

Part of the book: Concise Reliability for Engineers

By Jaroslav Menčík

Basic terms are explained, such as reliability, failure, fault, limit state, quality, safety, repair, renewal, maintenance, availability and dependability, inherent and operational reliability.

Part of the book: Concise Reliability for Engineers

By Jaroslav Menčík

The main concepts of probability theory are explained, such as probability, random quantity, population, sample, mean, average, standard deviation, coefficient of variation, probability density, distribution function, quantile, critical value, confidence interval and testing of hypotheses. Important probability distributions are also shown.

Part of the book: Concise Reliability for Engineers

By Jaroslav Menčík

The basic reliability characteristics are explained: time to failure, probability of failure and of failure-free operation, repairable and unrepairable objects. Mean time to repair and between repairs, coefficient of availability and unavailability, failure rate. Examples for better understanding are included.

Part of the book: Concise Reliability for Engineers

By Jaroslav Menčík

Typical time course of failure rate of unrepaired objects, called bathtub curve, is shown and its main stages are explained: period of early failures, useful life, and period of aging and deterioration. Attention is paid to the useful-life period, where the failure rate is constant and the distribution of times to failure (or between failures) is exponential. Illustrative examples are included.

Part of the book: Concise Reliability for Engineers

By Jaroslav Menčík

Many objects consist of more components. The mutual arrangement of the individual elements influences the resultant reliability. The formulae are shown for the resultant reliability of series arrangement, as well as for parallel and combined arrangement. The possibility of reliability increasing by means of redundancy is explained, and also the principle of optimal allocation of reliabilities to individual elements. Everything is illustrated on examples.

Part of the book: Concise Reliability for Engineers

By Jaroslav Menčík

This chapter explains the prediction of the time to failure in the following cases: fatigue of metallic components under cyclic loading or in the presence of cracks, static fatigue, wear and creep, variable loading (damage accumulation). Prediction of the time to failure based on monitoring of the changing response. Probabilistic aspects of the lifetime prediction. The determination of the time to failure is illustrated on examples.

Part of the book: Concise Reliability for Engineers

By Jaroslav Menčík

Various approaches to maintenance are explained: maintenance after failure (breakdown maintenance), preventive maintenance, on-condition maintenance, reliability centred maintenance (RCM), the use of technical diagnostics.

Part of the book: Concise Reliability for Engineers