Applied Mechanics and Materials Vol. 610

Abstract: The material model of cold deformation strengthened steel were studied. Firstly, on the basis of primary analysis for the material model, two assumptions are brought out. Then, on the basis that the residual stress and grain boundary state are detected, the constitutive equations are established by using affine transformation strain method.

Abstract: Efficient research method represents the primary content of hydrogen networks optimization. In the view of methodology, as pinch analysis is not specialized in precisely matching a network and mathematical programming is likely to induce convergence difficulties, a combination of both is liable to avoid their shortcomings. This paper introduces a detailed process, combining cascade analysis and mathematical programming method, to optimize a refinery hydrogen network with a purifier. A hydrogen cascade analysis instead of traditional pinch-point methods is deduced to rapidly obtain pinch-point purity without tedious iterative. On this basis, the location of the purifier could be pinpointed and a concise superstructure with pinch point and the purifier is constructed. Then a superstructure-based mathematical programming model is presented. A case study is finally carried out to examine the applicability and advantages of the proposed combination approach. The calculation result verifies the optimization of the method as well.

Abstract: A novel fabrication of degradable scaffold is presented by using several biomaterials and growth factor (GF). Chitosan fibers can be braided into the internal fiber microstructure of the scaffold by a three-dimensional braiding (3DB) method, and rapid prototype & rapid tools techniques can be used to rapidly fabricate the outer shape mold of the scaffold. The scaffolds with 3D fiber architecture had obviously accelerated bone regeneration in comparison with the control. In detail, the materials biodegraded inside and outside and the bone ingrowth first occurred along the chitosan fibers in the scaffold. In summary, the method in this paper not only can be easily shaped but also cannot change the bio-properties of materials and GF since it does not need high temperature sintering and not produce heat, so the actions of the several biomaterials for bone regeneration interacted simultaneously through the interconnectivity macrochannels in the in-vivo scaffolds, which left by the biodegradation of the internal fiber.

Abstract: This study used Taguchi plasma-sprayed experiments to determine the surface wear-resistant performance optimization of yttria partially stabilized zirconia (ZrO2/8Y2O3) coatings. Eight control factors based on L18 arrays were conducted and the wear-resistant properties of coatings were evaluated in the experiments. Based on analysis of variance, the optimal settings have been identified, and response surface methodology is utilized. Further, the contour nature of the quadric function is conducted to validate the tests in the Taguchi designed experiments. The experimental results obtained show that using an experimental design strategy with the proposed quadric model is useful not only for predicted optimal process parameters to achieve a desired quality but also for process optimization. Several response plots were generated to examine parameter effects on the response profiles. In addition, microstructures of the worn surface were examined, revealing a dense texture and highly anisotropic properties in the coatings with high anti-wear behavior.

Abstract: A two-dimensional mathematical heat transfer model for the prediction of temperature distribution within the slab has been developed by considering the thermal radiation in the walking-beam-type reheating furnace chamber and transient heat conduction in the slab, respectively. The steel slabs are heated up through the preheating, heating, and soaking zones in the furnace. Heat transfer characteristics and temperature uniformity of the slab is investigated by changing hot gas temperature. Comparison with the in-situ experimental data show that the present heat transfer model works well for the prediction of thermal behavior of the slab in the reheating furnace. The skid mark severity decreases with an increase in hot gas temperature. Keywords: Reheating Furnace, Thermal Radiation, Transient heat conduction

Abstract: This paper proposes an environmentally friendly energy-saving high-quality laser stamping foil film with particular seam-free feature. The whole idea is to meet the country's high-end anti-counterfeiting technology, consumer products packaging appearance, high-end gifts demand for the target material. The State Quality Supervision and Testing Center (Guangzhou) detection results shows that it includes many merits such as functionality, security, reliability, ease of use, flexibility, stability and other indicators, the performance meets or exceeds the requirements of enterprise technical conditions.

Abstract: Surface integrity is widely used for evaluating the quality of machined components. It has a set of various parameters which can be grouped as: (a) topography parameters such as surface roughness, textures and waviness (b) mechanical parameters such as residual stresses and hardness, and (c) metallurgical state such as microstructure, phase transformation, grain size and shape, inclusions etc. Surface roughness and residual stresses are among the most significant parameters of surface integrity, so that it is worth investigating them particularly. Many factors affect the surface integrity of machined components, including cutting parameters, tool parameters, material properties and vibrations. We can make prediction and optimization for surface integrity by taking advantage of these factors. This paper reviews previous studies and gives a comprehensive summary of surface integrity in the following order: introduction of surface integrity, main parameters of surface integrity, factors affecting surface integrity, prediction and optimization for surface integrity.

Abstract: In this paper the laser shock processing technology (LSPT) is investigated theoretically. A one-dimensional theoretical model is presented to express analytically the transmission coefficient of the incident laser beam through four different layers, i.e., the air layer, the constrained layer, the plasma layer, and the absorbing coating. Based on this model, the key parameters of LSPT can be further optimized to obtain the maximum transmission coefficient and the best surface-hardening effect. This one-dimensional theoretical model presented can be further used in guiding the parameter optimization for this technology.

Abstract: This paper studies the chemical combustion reaction of coke oven gas coupled with radiation heat transfer in the slab reheating furnace. Three dimensional temperature distributions of the produced gases and slabs in the combustion furnace are investigates numerically. Numerical results reveal that the radiation heat transfer dominates the heating process in the combustion furnace; it is around 95% of total input heating energy. The heating efficiency is examined for the sake of energy saving in the combustion furnace.

Abstract: Firstly, the importance and necessity of automotive eco-design were introduced. And then, the limit standards, testing methods and weight coefficient of basic indexes in assessment index system were pointed out. A linear-type dimensionless automotive eco-design assessment calculation method of individual index was proposed. Finally, the automotive eco-design assessment results calculation method was illustrated.