The Hydrodroforming Process of an Automotive Part Aminu
Tube hydroforming (THF) is currently an active area of development in the automotive industry on account of its advantages it offers in comparison to other manufacturing processes. In this paper, four simulations were carried out having the same cross sectional area but different axial feeding and load paths to improve the process design in THF process, in order to help establish the feasibility of the THF processes for specific components and have the potential to reduce the number of forming trials required to standardize the process for production of high quality hydroforming components.In addition, the studies also focus on development of an experiment simulation procedures for the entire hydroforming process. The simulation results focus on the % reduction thickness. It has also focus on the axial feed and load paths which becomes an important and useful method for planning the process design analysis, design of forming process and also planning of the tool. Since they play an important role and also determine accordance of forming limits such as wrinkling, bursting and crushing .The geometry model is analyzed base on different axial load and load paths. The key issues include geometry modeling, materials selection, meshing, boundary conditions, load definition and contact between the tube and the dies.On the base of the simulation, an optimized process parameter combination has obtained and has been verified by the instrument panel frame hydroforming experiment. The works show that:
Analysis of thinning at the transition corner in tube hydroforming
Abstract In tube hydroforming, the pressure for forming a small corner is far greater than other positions and thinning or cracking often occurs at the transition region between the corner and a straight side. To reveal the reasons of the local thinning and provide the clues to avoid the defect at the transition region, the stress distribution and deformation pattern of the corner are analyzed by mechanical analysis and numerical simulation. The effect of the friction coefficient on stress distribution is also considered. The material at the transition region much more easily satisfies plastic yielding conditions and produces compressive strain through the thickness. Therefore, severe thinning deformation easily occurs at the transition region. When the ratio of wall thickness to the corner radius is greater than 0.5, the difference of yielding conditions between the straight side and the corner is significant enough to induce serious deformation nonuniformity, even excessive thinning.
The Analysis on Fire Smoke Exhausting Robot Vibration Based on Wavelet Transform
Belt relaxation, which affects a lot on operation reliability of the fire smoke exhausting robot, is hard to detect. In this paper, a new method for belt relaxation feature recognition based on continuous wavelet transform (CWT) is proposed, and a vibration model which simplified the robot as a 2-dof forced vibration system under harmonic excitation is established. The vibration acceleration signal has been collected using the IEPE sensor and data acquisition card, experimental results verified the accuracy of the vibration model, and weak impact signal caused by the belt relaxation was distinguished, that testify the practicability of the CWT method in belt relaxation feature recognition.