Papers by Keyword: Cavity

Abstract: Taking the spatial pattern and the environmental elements as the starting point for the study of the ecological design of high-rise office buildings, this paper brings forward the concept of Eco-space Complex, structuring an open and dynamic spatial function complex as well as an eco-conditioning system..

Abstract: Knowledge based plastic mold cavity design and manufacturing system is presented. The system architecture is composed of user interface, application sub-system, feature technology, knowledge database and inference engine. The feature technology applied in this system includes feature recognition and feature matching which transforms the geometric model to feature model, and feature mapping which transforms product features into mold cavity features. Knowledge database and inference engine are critical for the knowledge based system. In this system, the knowledge database is divided into rule library and case library and the inference engine is integrated with Rule Based Reasoning (RBR) and Case Based Reasoning (CBR). The result shows that it can effectively integrate the information in the cavity design and manufacturing process and promote the mold design development.

Abstract: It’s very common that there are cavities after the lining and seriously affects the health of the tunnels. According to the status that the health standard is not uniform at present, the health levels can be divided into four parts: health, sub-health, disease and sick into death. For studying the single index criterion of lining cavities, and introducing lab large-scale model test combining the engineering example, analyzing the variety of structure bearing capacity, disease producing shapes and varying rule and so on where are different dimension cavities after lining. The results show that the carrying capacity curve expresses reverse S characteristic, it can be divided into slow, fast and complete degradation basis on the variety of velocity, and it is uniform to the sub-health, disease and sick into death, finding out the single health criterion of cavity: it is health where no cavities after the lining, it’s sub-health when the dimension is less than 100mm, disease when the dimension is between 100mm and 550mm, it’s sick to death if the dimension were more than 550mm.

Abstract: As a unique mode of soil erosion, loess cavities often act as the critical factor to the stability of the highway slopes of unsaturated loess. In this paper, the unsaturated loess slope stabilities are comparatively studied in different cases through the developed program of the strength reduction FEM, such as loess cavities in different position, single- & twin cavities, occurrence and loss of matric suction etc. The work done in this paper revealed the mechanism how the tunneling and the matric suction have effect on the stability of unsaturated loess slope to some extent. The results not only indicate that the loess cavities favor to maintain the stability of slope with the cavities located near the slope's crest, while the loess cavities reduce the stability of slope with the cavities located near the slope's toe, but also disclose that the safety factor of the unsaturated loess slope increases and the potential sliding surface move downward with considering the matric suction and vice versa. In addition, the twin cavities near the slope's toe have the obvious negative effects on slope's stability.

Abstract: The natural convection in a square cavity with a heated horizontal plate containing a nanofluid (water and Ag) is simulated numerically. The heated plate and vertical walls are maintained at a constant temperature, Th and Tc, while the horizontal walls are adiabatic. The nanofluid is assumed to be incompressible and the flow is considered to be laminar. The continuity, momentum and energy equations written in terms of the primitive variables are discretized using a control volume approach and the SIMPLER algorithm. A parametric study is performed and the effect of the Rayleigh number, the location of the heated plate and the volume fraction of the nanoparticles on the fluid flow and the heat transfer inside the cavity are investigated. The results show that the mean Nusselt number of the vertical walls increases with increasing the volume fraction of the nanoparticles. Moreover, for a constant volume fraction of the nanoparticles, the Nusselt number of the vertical walls decreases substantially as the location of the heated plate varies from top to bottom of the cavity.

Abstract: For getting the higher quality,the paper analyses the punching order according to the part shape,then determines the die styles.The dies include blanking and bending steps,the bending dies are choosed carefully,from the part to its’extension size,then to cavity size and punch size,thus the general assembly drawing is tested whether it is right.

Abstract: The cavity, formed at the nose part of underwater launched vehicle due to the high launching velocity, will collapse while crossing water free surface and has a great impact on the strength of vehicle structure. In order to study the effect of the cavity collapse to vehicle structure, water exit dynamic analysis has been conducted. Before that, the computational model has been established. The external load, caused by cavity collapse, is assumed to be concentrated pulse forces applied on the vehicle at different time. And the flight vehicle structure is simplified into a free-free Timoshenko beam. The Fluid Structure Interaction (FSI) effect is treated as added mass and hydrodynamic drag force varying with wet surface area, which decreases with the water exit of vehicle. The dynamic response, excited by the external load, is calculated. Result presents the necessary of taking account of FSI and the influence of time space between the two concentrated forces.

Abstract: A new type of resistance wind rotor with power-transmission cavity and three blades vertical axis is proposed. Computational Fluid Dynamics (CFD) is employed to numerically research the performance of blades in five typical rotation angles. The pressure of the wind rotor in the fluid field is got based on the static pressure contours of the blades in the five rotation angles. The simulation results show the positive pressure and the negative pressure appear around the blades in a cycle. Both of them can be motive power and resistance power to the wind rotor. The both power cancel out and the total torque output varies with the rotate location. Simulation results show that the largest torque appears at 90°while the least torque appears at 30°. Then, an instrument that measures torque output of wind rotor is designed. The torque output of the rotor in the five typed rotation angles is tested in a circle. The result indicates that distribution of the static torque output is like cosine wave in a cycle which is consistent with the results of the CFD. The studies provide the theory basis and the experimental introduction of the wind rotor designing.

Abstract: After superplastic tensile tests and quantitative analysis of cavity volume fraction, the damage evolution equation based on the law of the micro-damage evolution and statistical mechanics was derived out. The characteristic parameters of damage evolvement and critical value of damage variables are achieved from the experiments.

Abstract: Based on the strain energy function proposed by GAO Y C and the theory of finite deformation dynamics, the question about the cavity dynamic formation and bifurcation of the incompressible homogeneous solid sphere under a suddenly applied uniform tensile dead-load was studied. The condition under which a dynamic bifurcated solution exists was examined. The relationship between the dead-load and the cavity radius, the critical load, the stress distributions after the cavity formation, the vibration phase diagram of the cavity radius and the approximate vibration period were also determined.