Reliability test is an important technical means to evaluate and improve product reliability. It involves the formulation of test scheme, the development of test device, the recording of test process, the establishment of fault analysis technology and so on.
Purpose of Reliability Test
Reliability test is a test to analyze and evaluate the reliability of products. By analyzing the test results, we can not only determine the reliability index of the product, but also analyze the failure of the product, find out its weak links, and take corresponding countermeasures to improve the reliability of the product. From the purpose, reliability test plays a very important role in studying the reliability of products
Characteristics of Reliability Test
The reliability test is different from the routine test of the product. The purpose of the routine test is only to ensure that the parameters and physical and mechanical properties of the product meet the factory indicators during the factory acceptance, without measuring the failure rate of the product within the specified time. Therefore, there is no guarantee for the reliability of the product.
Reliability test ensures whether the product meets certain reliability indexes within the specified service time in the future. On this basis, reliability test enables the prediction and verification of product quality reliability.
In addition, in the processing of test data, the conventional test is only the passing test of performance, so the data processing is simple. Because the reliability test needs to infer the reliability of a batch of products, Jiayu detection network suggests that strict data statistical methods should be adopted in order to draw more reliable conclusions.
Due to the different purposes and requirements of the test, the test methods are also different. Therefore, we must distinguish between the two different concepts of routine test and reliability test, and must not replace each other.
Classification of reliability test
Reliability test covers a wide range of contents. According to the purpose of the test, reliability test can be divided into engineering test and statistical test.
The purpose of engineering test is to expose the defects in product materials, design, manufacturing and assembly, and put forward improvement measures to improve product reliability. The purpose of statistical test is to verify whether the reliability or service life of products meet the specified requirements.
Traditional reliability tests mainly include environmental stress screening test, reliability growth test, reliability development test, reliability verification test and life test; Accelerated reliability test mainly includes reliability enhancement test, accelerated life test and accelerated degradation test.
Environmental stress screening test
Environmental stress screening test refers to the selection of components, modules and complete machines under the condition of applied stress (vibration, impact, acceleration, temperature, etc.). Due to the inconsistency of raw materials and processes, differences in operation technology and quality control, there are some “hidden dangers” in the mass production of components. In the actual use process after being installed into the whole machine, it often leads to early faults and reduces the reliability of the whole machine. Therefore, the early fault products contained must be removed before the installation of components.
Reliability growth test
Reliability growth test is a test to expose the weak links of products, apply comprehensive environmental stress and working stress simulating the actual environment to products in a planned and targeted manner, so as to stimulate faults, analyze faults, improve design and process, and verify the effectiveness of improvement measures. Its purpose is to expose potential defects in products and take corrective measures to steadily increase the reliability of products.
Reliability development test
Reliability development test is a process of test, analysis and improvement, which is mainly applicable to the newly developed products by applying stress to the tested products to excite the material, components, design and process defects in the products into faults, and taking corrective measures to eliminate them after fault analysis and positioning.
Reliability verification test
Reliability verification test includes reliability identification test and reliability acceptance test. Both tests are to verify whether the product reliability meets the specified requirements by using mathematical statistics, so as to provide basis for product finalization. They belong to statistical test. Among them, the reliability qualification test is used to verify that the product has met the specified reliability index requirements before being approved for production, and provide the ordering party with the qualification certificate; The purpose of reliability acceptance test is to verify whether the reliability of batch products is maintained at the specified level.
Life test is a test conducted to determine the life of products under specified conditions. Its purpose is to verify the service life and storage life of products under specified conditions.
Reliability enhancement test
Reliability enhancement test includes high accelerated stress screening and high accelerated life test. It is a test to stimulate and expose weak links in product design by systematically applying gradually increasing environmental stress and working stress, so as to improve design and process and improve product reliability. We propose to accelerate the excitation of potential defects of products by using test stress more severe than the limit of technical specifications, which solves the problems of long time, low efficiency and high cost of traditional reliability simulation test.
Accelerated life test
Accelerated life test is a test technology and method to extrapolate or evaluate the life characteristics under normal stress level by using the life characteristics under high stress level by looking for the physical and chemical relationship between product life and stress – Accelerated Model on the basis of unchanged failure mechanism. It belongs to statistical test.
Accelerated degradation test
Accelerated degradation test is a test technology and method to extrapolate and predict the life characteristics at normal level by looking for the relationship between product life and stress (accelerated model) and using the performance degradation data of products at high stress level on the basis of unchanged failure mechanism.
Reliability test is applicable to most products. It plays a very important role in improving the production process and controlling the quality of products. DGBELL has more than 15 years of experience in the production of test equipment. If you need any relevant equipment, please feel free to contact us.