Earticle

Hydro-forming technology is a technology that will replace the existing press-forming technology and is used in various industry range from automotive parts to electronic products. The advantage of this technology is that it has dramatically changed the existing processing method, and it can be said that the process reduction due to the reduction of parts, cost reduction, and high precision are mentioned. In this study, it is intended to present a design process using computer simulation by changing the sub-frame for automotive parts produced with the existing press forming technology to the hide-forming method. To this end, it is intended to use it as part design data by comparatively analyzing the cross-sectional shape and thickness reduction, which are the major factors necessary to determine the successful development of the developed parts.

Hydroforming is a forming technology in which a steel tube is fixed in a die and formed to fit a specified design shape by applying hydraulic pressure from inside the tube. In present study, the whole process ofsub-frame side member development is presented by tube hydro-forming using steel material. At the part design stage, it requires feasibility study and process design aided by CAE (computer aided design) to confirm hydro-formability in details. Overall possibility of hydro-formable side member parts could be examined by cross sectional analyses. All the components is designed and formability is examined from the point of geometry and thinning. From the simulation results, the maximum thickness reduction rate is 55% after hydroforming. In order to improve this result, the feeding by 30 mm is applied to the both sides of the tube and the thickness reduction can be reduced from this management.

Hydroforming is a forming technology in which a steel tube is set in a die and formed to fit a specified shape by applying hydraulic pressure from inside the tube while also applying force in the tube axial direction (axial feed). In present study, the whole process of automotive cross members simulation and development by hydroforming technology to apply high strength steel is covered. At the part design stage, it requires feasibility study and process design aided by CAE(Computer Aided Design) to confirm hydroformability in details. Overall possibility of hydroformable cross members parts could be examined by cross sectional analyses. Moreover, it is essential to ensure the formability of tube material on every forming step such as pre-bending, preforming and hydroforming. At the die design stage, all the components of prototyping tool are designed and interference with press is investigated from the point of geometry and thinning.

The processing of forming deep hole in sheet is a kind of process using friction heat between drilling tool and workpiece to make workpiece in plastic deformation to machine hole. The process is a kind of green mechanical processing without chip. Studying green processing process in mechanical is becoming a development direction. In this paper, simulated analysis about the influence of processing parameters on the friction heat and the shape of forming hole, and researched on the temperature area of warm forming to machine hole, and then studied on quality of the hole in different temperature area in order to determine the appropriate warm extrusion temperature; Finally contrasted analysis the size of the hole of different location of test and simulation. The research results show that the simulation results agree well with the actual test results, and the warm extrusion is useful to form hole under the condition of a certain thickness.

The developing trend of Automotive Lightweight has brought about the application of High-Strength Steel sheet in the automotive body, but High-Strength Steel sheet has poor formability with cold stamping process, and the existing cold stamping process cannot fully meet the needs of high strength steel forming. The hot stamping technology of High-Strength Steel sheet is the effective method to solve the above-described problem. It can greatly shorten the tryout time of die, and can effectively solve some problems like discarding of die, unreasonable process, and poor forming quality etc. In this paper, mainly for the Thermo-Mechanical Coupling process of sheet metal, introduce the thermal field analysis of High-Strength Steel sheet, the interaction of deformation and temperature field, and the main steps of Thermo-Mechanical Coupling. And for the U Shaped part, built the Finite element model and set process parameters with software ‘Dynaform’. Simulated its forming process of Thermo-Mechanical Coupling with solver ‘LS-DYNA’. The changing temperature field, thickness, and thickness reduction rate were calculated. The results show that, Thermo-Mechanical Coupled Stamping Simulation is an effective method to forecast high temperature formability of High-Strength Steel Sheet.

In order to obtain the ideal parameters about influence degree of melting supplies and the ideal cooling structure of throat, and provide empirical datum for further research, this paper has used finite element method (FEM) to analyze a new type of FDM nozzle structure to study the effect of temperature on the nozzle head of different degree of melting of PLA supplies, the impact of different cooling air flow at the degree of melting of the PLA supplies, and the effects of differently cooling structure of the degree of melting of PLA supplies. The simulation results show that the heat dissipating structure with 195℃, nozzle temperature, 180 W/(m^2·℃) forced convection coefficient and Ф25mm heat pipe diameter of circumstances has good forming effect. In other words, the structure not only has an excellent performance in the throat but also could provide stable and reliable technical support for FDM prototyping equipment.