Papers by Author: Hao Zhang

Abstract: In order to give scientific and rational targeted support design of the roadway under the different rock conditions, ensure the safety of the roadway, and reduce support costs. By theoretical analysis, establishing the roadway hidden dangers grading mechanical model, proposing the method of tunnel fall hidden dangersclassification, on this basis, giving adaptive evaluation through existing branch of engineering analogy, loose circle test method, the theoretical calculations, numerical simulation methods supporting design methods, determining the theoretical calculation method based on the roadway roof stability classification for the design of bolt (Cable) support of roadway,giving the formula of roadway support parameters parameter quantitative. The same time, the research based on tunnel fall hidden dangers grading and the parameters design method of supporting, givingroof support parameter design examples of different surrounding rock level conditions anddifferent support mode.

Abstract: Machining simulation can quick supply valuable data to help improving machine processing quality and efficiency. And it is playing an important part in the development of modern machining theory. In this paper, the drilling process of an engine block was simulated in the software of DEFORM-3D. The geometry models of cutter and workpiece were simplified to avoid too low efficiency of simulation running. The mesh weight factors were specified to keep geometry models from changing too much from the real situation. 11 simulation experiments were carried out. And through regression analysis of the result data, the drilling load formulas were obtained to predict the axial force and moment in the drilling process of engine block.

Abstract: The recent investigations on spray formed ultrahigh-carbon steels (UHCSs) are reviewed. A satisfactory combination of strength and ductility in spray formed UHCSs can be obtained by hot rolling and annealing. The composition and hot rolling have a marked effect on the formation of graphite in UHCSs. The possibility of achieving high strain rate superplasticity in the spray formed UHCS was first revealed by very recent investigations in Shanghai Baosteel Research Institute. The UHCS processed by a combination of spray forming and hot rolling exhibited high strain rate superplasticity.

Abstract: Coatings of W on the substrate of oxygen-free Cu have been made by a high efficiency supersonic plasma spray system with a maximum power of 80kW and a maximum working at 6 m3/h flow of gas, and being compared with results of subsonic plasma spray. The bonding strength and thermal shock resistance of the coatings was tested. W/Cu functionally graded coatings is compared with single coatings of W.