Advanced Materials Research Vols. 887-888

Abstract: This work is focused on the study of orthogonal cutting of carbon fiber reinforced composite. A model based on finite element was developed. Through defining ultimate stresses of fiber tension cracking and fiber compression bucking, ultimate stresses of matrix longitudinal tensile and shear damage. Cutting forces obtained from the FE simulation matches well with the experimental observations. Than analysis cracking and crushing phenomenon of matrix in different fiber orientation, the influence of fiber orientation on sub-surface damage was studied, it shows that the cracking of sub-surface damage value increased with the increase of fiber orientation angle.

Abstract: The powder particles using the tool grinder is composed of two types . One is mounted on the rotating shaft of the machine tool . This tool is generally single cutting edge . The installation tool is a bolt shank fixed to the rotary shaft of the positioning groove . When you need to replace the tool mechanical enclosure open , loosen all bolts to remove the tool to replace the new tool . With no cutting edge tools can extend tool life. Reduce the number of replacement tools . The second tool is mounted on the housing of the machine tool . Single cutting edge of the tool mounting clearance is small, difficult to adjust the gap . Multi-blade cutter working gap can be formed when using the wedge mounting the inlet and outlet ports of the difference . Move the material in the resulting gap wedge and promote the formation of shear extrusion processing . Quick change fixed tool so that the tool sharp edge retention , reduce heat generation . Quick tool change involves cooling structure , the tool fixed way, the position of the discharge port design and rapid tool change .

Abstract: In this paper, a 6-DOF riveting manipulators kinematics model was built by D-H method, and its kinematics problems were discussed. Each of the kinematics parameters was gotten by solving the direct and inverse kinematics functions in Matlab. Then the virtual prototype model of the riveting manipulator was built by ADAMS, and the position, velocity and acceleration in the end center of the riveting manipulator were gotten by the simulation analysis. The reasonability of each linkage design parameters and kinematics model could be verified by simulation results in ADAMS, a foundation could be laid for the further dynamics research.

Abstract: This paper studied the performance of self-piercing riveting (SPR) and adhesive hybrid joints of different adhesive, including strength, capacity of energy absorption, failure mode and failure mechanism of the hybrid joints. The performances of SPR-adhesive hybrid joints were compared with SPR joints. SPR-adhesive hybrid joints and SPR joints were tested under a tension loading. The test results showed that adhesive have a function of improving the strength of SPR joints; however, the capacity of energy absorption of SPR joints was weakened. While the adhesive have no effect on the failure modes of SPR joints. When appropriate adhesive was selected, the overall performance of SPR-adhesive hybrid joints was superior to SPR joints. In a word, the combination of SPR and adhesive could get a well jointing structure.

Abstract: Clinching is a high-speed mechanical fastening technique for point joining of sheet material. In order to investigate the influence of material property on the mechanical property and failure mode of clinched joints, three types of clinched joints in aluminum alloy sheet were tested under tension-shear loading with MTS landmark, separately. Results showed that the property of the substrate had effective on the performance of clinched joints. Clinched joints had higher strength and good energy absorption capacity when the strength of the substrate was higher. The strength and energy absorption capacity of the clinched joints were evaluated via load-displacement curves. While the failure modes of clinched joints were all the same: neck facture failure.

Abstract: With the extensive use of new materials for aircraft structures, traditional riveting technology has been difficult to meet the demands of aircraft repairs. Laser welding of high concentration of energy is ideal technique for aircraft repair,because of its high welding speed, small heat-affected zone, perfect welding joint and small deformation of the welded structure. This article analyzes the application of laser welding technology in aeronautical aluminum alloys, titanium alloys and superalloys aircraft damage repair.

Abstract: SSM 356 aluminum alloys was obtained from a rheocasting technique named gas induced semi solid process has globular structure on base. The friction welding method conserve microstructure that is similar to the original structure of the base material a globular structure. It is also found that a rotational speed of 1750 RPM, burn of Length of 3.2 millimeters and welding time (upset time) of 30 second can produce a very good weld. The results of the investigation have shown that a have average hardness in the range 58.13 HV.

Abstract: Transient temperature fields during formation of dissimilar butt joints of Ti-Al alloy plates by laser welding process were investigated by numerical simulation. Gaussian volumetric heat source was applied to model the heat input to the weld. For verification of the developed simulation model and results of numerical simulation, Ti-Al butt weld joints were produced by TruDisk 4002 disk laser. During experiments, the temperatures were measured by thermocouples and subsequently compared with results of FEM analysis. Based on the results of preliminary numerical calculations and experimental tests, the parameters of the laser beam welding for production of dissimilar Ti-Al butt joints will be optimized using FEM simulations in the program code ANSYS.

Abstract: The static stiffness and numerical modal are analyzed with the finite element model of a heavy duty truck cab. Considering the influence of welding spots on static stiffness, strength and first order modal frequency, the welding spots of the heavy duty truck cab are divided into two areas based on element strain energy density. And welding spot layout of the two areas is optimized by topology optimization method respectively. Then the robustness of welding spot layout before and after optimization is analyzed. The results show that the number of welding spots after optimization is reduced with the performance maintained and welding spot layout robustness of the cab is improved.

Abstract: By means of the high speed camera, the arc and drop transfer behaviours of direct current electrode negative MAG welding process are researched. The influences of luminous arc ball on the stability of MAG welding process are analyzed. On this basis, the process interval of DCEN MAG welding is determined. And the influences of wire polarity on wire melting coefficient are compared. By using the shield gas 98%Ar + 2%O₂, the stable drop transfer manner can be divided into two kinds: dropwise transfer with low current, and streaming transfer with high current.