This paper proposed a type of new parallel tilter with four degrees-of-freedom, whose moving platform has three rotations and one translation. The coordinate transformation is adopted to establish the position and velocity kinematics equation of the tilter. Simulation result indicated that the moving platform can move according to the set law by modifying the displacement of the piston rod in active limb.

Composite patch adhesively bonded repair is an advanced repairing method for damaged metallic structure, and in patch designing, it is important to choose appropriate geometrical parameters, which decides mechanical properties of repaired structure. Based on 3D FEM, the model of aluminum plate with a central through crack adhesively bonded repaired with carbon/epoxy composite patch was established, which can take into account residual thermal stress and bending deformation caused by differences of thermal expansion coefficient. SIF was calculated using virtual crack closure technology and compared to evaluate effects of patch geometrical parameters on mechanical properties of repaired structure. The results show that there is optimal patch length and thickness which can make best repairing effect and an effective patch width can reduce SIF significantly, beyond which it is helpless.

Elastic constants of purity and containing impurity metal aluminum were calculated, and the effects of impurity on the elastic constants were also studied. The effect of particle on micro-stress concentration and debonded stress of inclusion was researched. The mechanical relationship between the grains was defined by relationship of displacement and driving force in cohesion zone model (CZM).The method can be extended to research mechanical properties of other metals and alloys structures.

According to the configuration theory of the parallel manipulator with a few degree of freedom (DOF), the paper adopted 2PSU-U mechanism to design a new parallel tilter with 2 DOF, which has such advantages as strong bearing capacity, high precision and kinematic decoupling. It used the coordinate transformation to establish the position and velocity equations of the tilter, and also used the instance to make kinematic simulation, whose result indicated that the roll and pitch angle of the moving platform can vary according to the set motion law by driving two sliders of the main moving branched chains.

One type of spatial new parallel mechanism with two degree of freedom is proposed.. The position and velocity analytic equation are constructed based on the coordinate transformations. Finally, the singular configuration of the tilter is analyzed by the forward and the inverse Jacobian matrix.