Finite element comparison of single, bi-layered and three-layered tube hydroforming processes
In this paper, single, bi-layered and three-layered tube hydroforming processes were numerically simulated using the finite element method. It was found that the final bulges heights resulted from the models were in good agreement with the experimental results. Three types of modeling were kept with the same geometry, tube material and process parameters to be compared between the obtained hydroformed products (branch height, thickness reduction and wrinkling) using different loading path types. The results were also discussed.
Experimental Investigation and Numerical Simulation of the Mechanical Behavior of a Novel Honeycomb Core Sandwich Panels Formed by Hydroforming Process
Sandwich panel with central core honeycomb aluminum as one of the main shielding structures because of their high strength-to-weight ratio and improved energy absorption capacity, has been attracted the attention of many researchers and pra ctitioners in recent years. This paper initiates an d presents a new type of central core honeycomb forme d by hydroforming process. The study is augmented by a numerical and experimental work on f lexural behavior of sandwich panel structures made of aluminum alloy and different cores such as aluminum, polyurethane foams, PVC, silicone and carbon fiber. Firstly a numerical simulation by ABAQUS software was run, then prepared samples were tested and related force-displacement diagrams were depicted from results. Comparing the corresponding diagrams obtained from si ulation with that of the results of experimental investigation, high flexural strength of the sandwich panels with proposed honeycomb core relative to a three-layer sheet as well as a v ery high flexural strength of suggested sandwich panel with honeycomb core filled with carbon fiber against other samples of honeycomb was observed. Finally, comparing the experimental resul ts with numerical simulations indicates acceptable conformity.
Study on hydro-forming technology of manufacturing bimetallic CRA-lined pipe
Abstract An improved hydraulic expansion device for manufacturing CRA-lined pipe has been proposed and developed to overcome the disadvantages in existing fabricating technologies. The mechanism of hydraulic expansion method is diagrammatized, as well as the stress and strain in the liner and the outer pipe have been analyzed theoretically during the hydro-forming process. According to the true stress–strain curve of pipe materials, the more accurate calculating formula relating hydro-forming pressure and residual contact pressure between the liner and the outer pipe is obtained. The theoretical analysis is verified by experimental investigation, the test results demonstrate that the new technology is feasible and can be applied in industrial production.