PSI - Issue 57

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Karthik Krishnasamy et al. / Procedia Structural Integrity 57 (2024) 793–798 Karthik KRISHNASAMY/ Structural Integrity Procedia 00 (2019) 000 – 000

Fig-1: VALEO portfolio for electric drives from low to high-end applications.

E-Bike to high-end premium and light commercial vehicle with most sophisticated systems and these modern products are is confronted with rising functionalrequirements, higher complexity, integration of hardware, software, sensor technology and with reduced product development cost. To achieve customer satisfaction, system reliability to be examined during the complete product development cycle from the viewpoint of the customer, who treats reliability as a major topic and VALEO committed with the statement to the product reliability. A key component in all these electric drives is the reducer, which transfers the power to wheels. Reducer is designed for a given life time, as an example of 10000 hours with target reliability and it should behave in such that, all the components should have same lifetime and not more, for cost reasons – but this could be questioned as Remanufacturing can a lso be planned at design stage. Why, since the failure of the first critical component normally determines the complete reducers end of life. So overdesigned components generates unnecessary costs to the consumers. Engineers in VALEO state the design based on such requirements right from the initial phase of the development, but the method used to achieve the requests vary, also the involvement of different domain specialists and experts. Design elements developed from simple assumption to the most sophisticated models. All these methods delivers a safety factor at the end, which is limiting stress over induced stress.

Nomenclature R

Reliability.

n c

Required number of cycles.

T β Weibull scale parameter (Characteristic lifetime). Weibull shape parameter. F s & F r Cumulative distribution function of stress & strength. f s & f r Probability density of stress & strength. t o Load cycles without failure. B Achievable life. Rc Individual component reliability. Rs System reliability.