Failure Analysis and Design Modification of Mandrel in Chassis Tube Bending Machine

Abstract

Tube/pipe bending is crucial in the automotive industry, especially for rectangular chassis tubes that serve as vital structural components. However, the fatigue life of these tubes can be compromised by surface defects, loads, and vibrations, leading to hazardous failures. Wrinkles and shrinkage often occur during bending due to compressive stress. Mandrels are used for internal support, but they are susceptible to fatigue failure. This research analyzes three fractured mandrel specimens to guide design modifications. CAE analysis simulates real-world conditions, validating the design and predicting durability. The optimal mandrel design based on CAE simulation results will be manufactured for rotary tube bending machines, improving performance and reliability. This research aims to build confidence in finite element simulation, saving time and cost. It also highlights the significant impact of the heat treatment process on component fatigue life, enabling them to withstand rough service conditions.