Applied Mechanics and Materials Vol. 387

Abstract: Burning the industrial solid waste can form low melting point alkali salts to cause heavy sinters in the incinerator. The utilization of additives is proved to be effective to reduce the sintering in this work. Three additives (lime, kaolin and coal ash of an electric power plant) were mixed in different proportions with the industrial solid waste, and then an ash fusibility test was performed on the solid waste and the mixtures. The results show that, the solid waste exhibits a low melting point and the chemical additives can increase it efficiently. Furthermore, the anti-sintering mechanisms may conclude that the additives react with the alkali salts in the solid waste to form the high melting point materials.

Abstract: To discuss the modeling method and simulation analysis of multiple degree of freedom vibration system by using the Maple/MapleSim simulation software, the seismic response of the ground buildings model and the torsional vibration of gear shaft model are used as examples respectively. The application of MapleSim in the process on signal analysis, extraction of the dynamic equation and solution of the natural frequency of multiple degree of freedom vibration system are expounded concretely. While the modeling speed is improved, this method also reduces the programming process and the difficulty of programming. It provides an effective reference for handling similar multiple degree of freedom vibration system simulation.

Abstract: Stagnation flow, an import research branch of fluid mechanics, describing the fluid motion near the stagnation region, exists on all solid bodies moving in a fluid. And stagnation point boundary layer flow problems described by partial differential equations have attracted many scholars attention nowadays. These problems have become difficult and hot in the study of applied mathematics, mechanics and materials engineering. This paper has transformed the governing boundary layer equations into a system of nonlinear differential equations through the similarity transformation, and the analytical approximations of solutions are derived by homotopy analysis method (HAM). In addition, the effects of physical factors (such as the slip parameter, Magnetic field parameter and Reynolds number) on the flow are examed and discussed graphically. They have a great impact on the speed.

Abstract: s: Brain impact injury is the leading cause of death in traffic accidents. In this paper, a brain multi-functional rotary impacting platform will first be set up. After this, the living animal brain sagittally rotary impacts will be executed and the injury tolerance will be achieved. Then, the sagittal physical models of animal and human brains will be produced and the four-point markers will be placed widely on the models sagittal sections. In succession, the high-speed camera and the three-dimension infrared motion analysis meter will be used to record the rotary impacting process, the exterior angular acceleration course and the shearing strain data of interior four-point markers. Thus, with the exterior angular acceleration course, the living animals experiments and the experiments based on the animal physical brain model can be coupled equivalently. In the same way, through the maximum shearing strain data of interior four-point markers, the experiments based on the animal physical brain model can be equivalently coupled with the experiments based on the human physical brain model. Finally, according to the comparability in pathology and physiology between animal and human brain tissue, the injury tolerance of human brain under its sagittally rotary impacts can expect to be obtained through the mechanics study.

Abstract: Based on the modal superposition method, the analytical model of vibration and sound radiation from submerged double cylindrical shells with damping layers was presented. The shells were described by the classical thin shell theory. The damping layers were described by three-dimensional viscoelastic theory. The annular plates, connecting the double shells, were analyzed with in-plane motion theory. For different drive locations of radial point force on the inner shell, the sound radiated power and the radial quadratic velocity of the model were calculated and analyzed. The results show that making the drive location near the annular plate helps to reduce the sound radiated power and radial quadratic velocity of model, and making the drive location far from the middle of model also helps to reduce the sound radiated power. The drive applied on the location of annular plate causes high similarity of vibrations from inner shell and outer shell.

Abstract: A numerical model capable of calculating the strength of 3D braided composites is developed, based on the micro-structure of 3D four-directional braided composites and the assumption of the braiding yarn with a helix configuration and ellipse cross-section. The strength of 3D braided composites have been predicted through a finite multiphase element method (FMEM). Comparison was conducted for those from the present model and experiment. The results are in good agreements with the experimental results in the previous literature. The influences of braiding angle on the strength are also studied.

Abstract: The health diagnosis of seismic-damaged tunnel seismically damaged is important in recovering traffic lines for seismic relief and recovery. Taking a tunnel damaged tunnel in the Wenchuan earthquake as an example, the methods of safety check is exposed. The non-destructive test showed that the seismic damage to this tunnel included concrete cracks, hidden cavities, and strength deterioration of lining. Several causes induced in seismic diseases were discussed. The rehabilitation technique, which needs not break off transportation through the tunnel, was also put forward. It is hoped that this earthquake mechanics study can enhance the stability assessment and tunnel reinforcement in a highly seismic region.

Abstract: Be aimed at concrete surface damages of hydraulic concrete structures, a high strength repairing mortar was made in this paper. The mechanical properties and durability of repairing mortar were studied. Samples of repairing mortar preparation in laboratory and in field were tested respectively and its repair process and quality control was discussed. The results show that the repairing mortar has good mechanical property, obviously anti-abrasion property and excellent bonding performance. It can play an important role in concrete repairing in the field of hydraulic engineering. The sample property from field is a little lower than of laboratory made but still superior to design index. To achieve good repairing effect, construction technology and quality control is also the important factor.

Abstract: The expression of vertical vibration mode-function of fluid conveying pipe supported elastically on two ends was derived from the boundary conditions of similarly supported beam. The dynamic stability of pipe conveying fluid with the same supporting conditions was invesigated and the expression of its critical instability flowrate was obtained. The effects of fluid pressure and axial force of pipe section on critical instability flowrate were calculated and analyzed based on the eigenequation. The numerical results showed that the critical instability flowrate were proportional to axial drawn force, but proportional conversely to fluid pressure and axial pressed force of pipe section. The critical instability flowrate of fluid conveying pipe varied greatly with its supporting conditions. In order to improve its value at engineering application, the axial pressed force of pipe section should be avoided.

Abstract: The silicone rubber foam is a suitable material used for heat insulation and vibration reduction. Because of dispersion of its mechanical character, it is difficult to quantify the assemble stress in reliability analysis. Based on reduced hyper-foam Ogden Model, the interval of model parameter is obtained through fitting the test data, and the predicted assemble stress distribution is also achieved by Monte-Carlo random simulation method. Then, the regression analysis of predicted data estimated is introduced by the extreme value distribution. The predicted assembly stress distribution described in this paper achieves high confidence by the extreme value distribution. Thus, combined with strain uncertain quantification, the reliability analysis of assemble stress can be performed.