Reliability Prediction of a Mechanical Component Through Accelerated Life Testing

Abstract

The reliability prediction (i.e. life prediction) of components and subsystems is a crucial issue for the efficiency of production systems. This paper presents a reliability assessment method, applied to a mechanical component (i.e. gear unit) of an automated manufacturing system. Study is based on accelerated life test approach (ALT). In the study authors used General log-linear model (GLL) combined with a Weibull distribution for time to failures. Researchers did different experimental tests in the laboratory of the Department of Industrial Engineer -University of Bologna, to estimate model parameters. Expected life of component was then evaluated using the proposed ALT model. Finally, results are compared with actual time-to-failure data coming from field. Time-to-failure was collected during about 10 years, on about 20 production lines using the same gear unit. The accordance between real data and life prediction is satisfying. Results confirm Accelerated Life Testing (ALT) is an efficient and effective assessment method for lifetime prediction based on short time tests.

Reliable Method to Detect Alloy Soldering Fractures under Accelerated Life Test

“…In the failure mode effect analysis, the fracture in the soldering alloy was the highest failure mode with a Level of Risk Priority (LRP) of 300, which is due to the soldering alloy found in the pines of each component allowing the current flow. With the FTA, the causes of the failure were found, which are the temperature and vibration [9][10][11][12][13][15][16][17][18][19][20].…”

“…This allowed definition of the different combinations of the variables that duplicate the failure modes in minor time compared to the traditional methods. Table 1 shows the optimal experimental design obtained to realize the different combinations of the variables and its level, where -1 represents the low level and 1 represents the major level [10][11][12][13][15][16][17][18][19][20][21][22][23]. 24] made the corresponding calculations of the statistical analysis and the experiments design for calculating the accelerated factor of the temperature test.…”

“…Likewise, many authors have been using analytical methods such as the Failure Mode and the Effects Analysis (FMEA) [9,10]. Furthermore, advanced statistical methods as well as the Taguchi design have been used to select the best combination of parameters; however, the approach of variables includes all the electronic assembly [11][12][13][15][16][17][18][19][20]. In this research, a development and design of the ALT is presented, as well as its approach towards the material waste.…”

“…A ductile fracture occurs when the soldering alloy is exposed to plastic deformation due to stress caused by damage including excessive tensions such as thermal variation or mechanical effort. In some research [6][7][8][9][10][11][12][13], it is mentioned that mechanical effort causes parallel cracks, and thermal variation generates a network of multiple fissures. Furthermore, there have been fracture analyses using measures of resistance and visual inspection.…”

“…Consequently, the reported data come from a truncated distribution and the number of uninformed premature failures is unknown. Inferences are developed for a Weibull ALT model in which transformed scale and shape parameters are expressed as linear combinations of environmental functions (stress) [11][12][13][15][16][17][18]32,[36][37][38].…”