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Precision spherical joints are widely employed in parallel mechanisms, but its rotation orientation and angle can not be known in its passive motion. Measurement of multi-dimensional angular displacement will be very of great significance in the prediction, feedback and control of motion errors of parallel mechanism. Based on the magnetic effect, a new method to identify the orientation and rotation angle with Hall sensors array matched by permanent magnet is proposed. The basic idea is embedding a permanent magnet(PM) in the ball head and several hall sensors are distributed in the ball socket. When the ball head carrying the permanent magnet rotates together, the Hall sensors array will detect the variation of magnetic induction intensity, and then the angle can be calculated by mathematics model.

Shearography is widely used in nondestructive testing because it has the advantages of full-field, robust, non-contact and high sensitivity. However, conventional shearography can only measure the first derivative of deformation in a single direction; multiple tests need to be done to obtain the first derivative of 3D deformation in different shearing directions. This paper presents a novel shearography system that simultaneously measures the first derivative of 3D deformation in two orthogonal shearing directions, one is in the x direction and the other is in the y direction. This system achieves dual-directional shearography by a modified Michelson interferometer. The object surface is illuminated by three different wavelengths of laser in different directions and a 3CCD color camera is used to record images. Different color shearograms recorded by 3CCD color camera were extracted respectively through channel separation, and cross talk does not exist.

Light-weighting vehicles cause an increase in Aluminum Alloy stamping processes in the Automotive Industry. Surface finish and lubricants of aluminum alloy (AA) sheet play an important role in the deep drawing processes as they can affect the friction condition between the die and the sheet. This paper aims to develop a reliable and practical laboratory test method to experimentally investigate the influence of surface finish, lubricant conditions, draw-bead clearances and pulling speed on the frictional sliding behavior of AA 6XXX sheet metal. A new double-beads draw-bead-simulator (DBS) system was used to conduct the simulated test to determine the frictional behavior of an aluminium alloy with three surface lubricant conditions: mill finish (MF) with oil lube, electric discharge texture (EDT) finish with oil lube and mill finish (MF) with dry lube (DL).

It was simulated the temperature and thermal stress distributions of ceramics/metal functional gradient piston coating based on the third type boundary conditions of piston in IC engine under stable working conditions using the indirect solution method of thermal analysis and subsequently structural analysis by means of ANSYS10.0 finite element software. It was studied the effect of gradient composition distribution index p on the temperature of piston head and the thermal stress at the gradient layers of ceramics/metal. The optimal design result, as the gradient composition distribution index p = 0.6, could be obtained to relax the thermal stress.