Advanced Materials Research Vols. 378-379

Abstract: The anoxic, anaerobic and aerobic reactors were used to treat rural domestic wastewater, single-stage reactor inoculated with different sludge was optimized, and the removal efficiencies of CODCr and TP were discussed. The results indicated that the anoxic and anaerobic reactors inoculated with anaerobic sludge could be selected as the effective unit for the anoxic/anaerobic /aerobic process. The removal efficiency of CODCr could reach 95.1%, the effluent CODCr was 25.7mg/L~97.2mg/L, the removal efficiency of TP could reach 97.1%, the effluent TP was 0.24mg/L~0.96mg/L.

Abstract: To analogy and calculate the force distributed characteristic of external force of stem to transmition toward the root system by the SM Solver, and take the roots of Caragana microphylla Lam. and Artemisia sphaerocephala krasch. as the object of study in this paper. The results showed that the force of two plants mainly bears by the main roots, and the force of main roots decreases with the increase of soil depth. Force of main roots of Caragana microphylla Lam. and Artemisia sphaerocephala Krasch. at most reach 89℅ and 98℅ of external force of stem, Force of First-level roots of Caragana microphylla Lam. and Artemisia sphaerocephala Krasch. at most reach 14℅ and 10℅ of external force of stem, and that of second roots of Caragana microphylla Lam. and Artemisia sphaerocephala Krasch. is only 2℅ and 0.3℅. Force decreases with the increase of root length and depth, and the force increases with the increase of included angles between roots and vertical line.

Abstract: Based on the two-dimensional elasticity,the symplectic method is applied to study analytically the stress distributions of anisotropic beam.Using variation principle and introducing separation of variables, dual equations were presented.Then in the symplectic space which consists of the original variables and their dual variables,the problem can be solved via effective mathematical physics methods such as the method of sepatation of variables and eigenfunction vector expansion.So the original problems come down to solve the eigensolutions of zero eigenvalue and non-zeroes eigenvalue that describe the exponentially decaying localized solutions usually ignored by Saint-Venant's principle. Completed numerical examples are newly given to compare with established results.

Abstract: Based on application characteristic of hydraulic retarder in combined braking, the generant mechanism of air losing is analyzed, by adding baffle-plate setting, air losing is reduced. Using CFD technology, the ameliorative hydraulic retarder is studied contrastively, and the results are in good agreement with the experiment.

Abstract: Analytical models of the actual structure often differ greatly from their as-built counterparts. Model updating techniques improve the predictions of the behavior of the actual structure by identifying and correcting the uncertain parameters of the analytical model. This paper presents a new model updating technique to improve the finite element analysis model by updating design parameters using strain measurement based on affine scaling interior Algorithm. Static strain measurements are more reliable and realistic than acceleration data in practice. Numerical examples are presented to study the application of the method.

Abstract: The paper is concerned with using experiments and numerical simulations to study the mechanical performance of a Honeycomb Fiber-Reinforced Polymer (HFRP) sandwich panel at different temperatures, especially at low temperatures coupled with cyclic loadings. All physical tests were performed in a temperature controlled room and used a three-point bending setup where the applied load gradually increased from zero to 36kN. Experimental results show that the stiffness of the panel becomes softer at some lower temperatures. In order to eliminate the influence of the initial conditions, an incremental method was introduced to process the experimental results. This method treated all displacements and strains as zero when applying a load of 4.5kN. Furthermore, the change in stiffness of the panel was obtained through the use of a special equivalent stiffness which involved measuring the change of the stiffness of the panel. After comparing different methods, the composite shell method was used to build finite element models for numerical simulations in ABAQUS. Reduction of moduli and Random Mesh Size Method (RMSM) were employed to simulate microcracking between fibers and matrix and debonding between the core and face sheets, respectively.

Abstract: The Al-40Si alloy modified by 1.0 wt% Sr addition was heat-treated using L9(34) orthogonal test. The mechanical properties were measured. The microstructures were analyzed using optical microscope. After heat treatment, the hardness decreases about one times. The eutectic matrix and primary Si phase are both refined. The primary Si phase is refined and homogeneously distributes in the matrix with the solution temperature and time increasing. The optimal heat treatment condition is that the solution temperature, solution time, aging temperature, and aging time are 550 °C, 18 hours, 200 °C, and 5 hours, respectively. In addition, the theoretical optimal value for the hardness is 20.6 HRC, which is coherent with the practical optimal value.

Abstract: For concrete perforated brick wall has drying shrinkage cracks during the construction and use which is the prevalent phenomenon, combined with structural reliability theory, used of the basic theory of linear elastic fracture mechanics, when block wall construction was in the production of drying shrinkage cracks the reliability of crack resistance were analyzed and calculated which is a useful complement that reliability analysis and a useful level adjustment of reliability in the "code for design of masonry structures".

Abstract: Thick-walled hollow cylinder is an important class of engineering structure, the stress state of which depends on the loads and properties of the body materials. Under the assumptions of σθ-σr=c (σθ and σr denote the hoop stress and radial stress, respectively, c is a constant), inverse analysis of thick-walled hollow cylinder composed of functionally graded materials with uniform pressure acting on the outer surface is carried out. Analytical solutions for the Young’s modulus variation in the radial direction are obtained. It is found that only when the Young’s modulus E(r) is a specific monotone increasing function of the radius r, the pre-specified stress distribution can be satisfied. Comparing with classical homogeneous materials, stress concentration at the inner surface of hollow cylinder composed of functionally graded materials can be alleviated. Hence the elastic ultimate bearing capacity of hollow cylinder can be improved strikingly. For functionally graded materials, the elastic ultimate bearing capacity can be improved strikingly by increasing the thickness of cylinder, which is not so obvious for classical homogeneous materials.

Abstract: Owing to the excellent properties, carbon fiber composites have been applied in many fields. This article outlined the new applications and development trends of carbon-fiber composite materials, and pointed out some problems existing in their development. Moreover, a new kind of billiard cloth made of the mixture of carbon fiber composites and wool was argued in the paper.