Papers by Author: Zhao Qian Li

Abstract: Based on failure mode analysis of the cermet cladding part, the last layer failure assumption is adopted and the method to establish reliability model of the cladding part based on the failure tree series is proposed. Theoretical and example investigations are carried out. The failure tree series for the failure process of the cermet cladding part under the mechanical impact are established.

Abstract: Enhancing the reliability of product becomes one of the most important ways to perfect its quality. Based on the traditional reliability definition, the definition of assembly connection reliability is presented to describe the connection ability of two assembled parts firstly. Then, the design method based on assembly connection reliability is proposed and a new step-by-step mathematical model for assigning assembly reliability to the parts and sub-systems is established. Based on the model, design scheme oriented assembly reliability is optimized.

Abstract: Basing on the theoretical study on the stress intensity factor (SIF) of the crack inclined across the interface of the cermet cladding part, the finite element analysis (FEA) of the crack’s SIF is made. The change laws of the SIF with the load action angle , the load Q, the clad thickness ratio h1/h, the elastic modulus ratio E1/E2, the inclined angle of the crack β1, and the crack length ratio a1/a2 are obtained. The research results have theoretical and steering significance on the wide application of the cermet cladding part.

Abstract: Basing on the theoretical study on the stress intensity factor (SIF) of the crack normal to and dwelling on the interface of the cermet cladding part, the finite element analysis (FEA) of the crack SIF is made. The change laws of the SIF with the load action angle, the load Q, the clad thickness ratio h1/h and the elastic modulus ratio E1/E2 are obtained. The research results have theoretical and steering significance on the wide application of the cermet cladding part.

Abstract: Basing on the theoretical study on the stress intensity factor (SIF) of the crack parallel to and lying on the interface of the cermet cladding part, the finite element analysis (FEA) of the crack’s SIF is made. The change laws of the SIF with the load action angleψ, the load Q, the clad thickness ratio h1/h and the elastic modulus ratio E1/E2 are obtained. The research results have theoretical and steering significance on the wide application of the cermet cladding part.

Abstract: Computer-aided design tolerances (CADT) technology got far behind the CAD, CAPP, CAM etc, although there are many commercial tolerance software, but the tolerance optimal design still can’t be completed, which seriously affects the CAX technology's integral roles. Based on the tolerance computation function of the UG Quick Stack module, this paper accomplishes the product assembly relation modeling, tolerance distribution, locked circle calculation and so on, achieves the optimal design tolerance of whole product.

Abstract: In order to protect ERP system information from authorized users or non- trusted users, a trusted role based access control model was proposed. Combined with the characteristics of enterprises, trusted computation for user is designed to support roles assignment to the users. Meanwhile, Object Lifecycle States (OLSs) are presented for efficient access control to objects. Based on the value of trusted computation, users are assigned the corresponding roles to access control various resources. Finally, there is an empirical research on an ERP System implemented in a manufacturing enterprise.

Abstract: Thermal shock properties of Q235A steel used ternary-boride-based (TBB) cladding material has been studied. The result indicates that this cladding material has excellent resistance to thermal shock and that the cracks are not difficult to occur at the interface of cladding layer and steel substrate. The mechanism of thermal shock failure is fatigue failure brought by cycle stresses. The thermal shock has little influence on the hardness of cladding layer. The structure of cladding layer has no obvious change after the thermal shock, but the phase of steel substrate change from ferrite and pearlite to martensite.

Abstract: The interaction between a cermet cladding plate part and a homogeneous cylindrical part under wear condition is simplified as a plain strain contact problem. Based on Hertz contact theory, the theoretical model of the maximum shear stress in the cladding part is built; an example and its finite element analyses (FEA) are given. Theoretical results well coincide with those of the FEA. Both results show that, with the increase of the cladding thickness, the maximum shear stress decreases, its position shifts toward the clad surface. The effects of the wear load and the properties of the frictional materials on the maximum shear stress are also studied. The research results have great significances to the design of cladding parts under wear condition.

Abstract: Using Mo powder, B-Fe alloy powder and Fe powder as raw materials, adding Ni and Cr respectively, with proper forming additives, the green body is formed by coining. The ternary boride hard alloy material is fabricated by liquid phase sintering technology. The influence of different content of Cr and Ni on mechanical properties is studied respectively. The optimal content of Cr and Ni and the optimal temperature are found.