Applied Mechanics and Materials Vols. 170-173

Abstract: Reinforced concrete (RC) frame structure is one type of building structure which is widely used in China. Damage of some reinforced concrete frame structures under the earthquake is caused by the damage of beams and columns, so beams and columns are essential seismic members. However, the test datum are not enough to study the performance of RC beams and columns , Therefore, Finite element simulation of RC beams and columns is performed by software ABAQUS in the paper. Through comparing with the finite element simulation and the test of load - displacement skeleton curve, failure mode and steel bar strain, the result shows that the finite element simulation can more accurately simulate the situation of the test and verifies the finite element simulation is the most important research tool besides test.

Abstract: The primary goal of emergency evacuation for pedestrians is evacuating as many people as possible to safe areas in a shortest time when the accident occurred. And the primary factor of pedestrian evacuation is egress. According to the literature, we can know that the reasonable design of the evacuation corridor and the right guidance to pedestrians are very important, and analyzed main affect factors to the evacuation corridor, which affect of the evacuation speed for corridor at different pedestrian flows intensity, the width of evacuation corridor, setting canalization to corridor and the size of space of corridor peripheral. This paper use VISSIM simulation software to study on pedestrian flows evacuation. So the formulation for pedestrian evacuation program should consider a variety of elements for the design of the evacuation egress and corridors to increase efficiency and reliability for pedestrian evacuation.

Abstract: Four-bar linkage mechanism of the hydraulic support is designed by means of analytical and graphical method. A 3D kinematics model with Pro/E software is set up for the hydraulic support. The simulation analysis and interference of the hydraulic support is carried out and the motion path of the four-bar linkage mechanism under the real project condition is shown. The simulation result shows that the design of the four-bar linkage mechanism is reasonable and the designed hydraulic support meets its actual work requirements.

Abstract: Recently, the quantity of the cold store has been increased quickly. It is a key point to improve the uniformity of airflow field to the cold store. In this paper, a model of simulating cold store by computational fluid dynamics (CFD) was introduced. Simple algorithm combined with Boussineq assumption was used and turbulent equation combined with standard wall function was applied to define the flow of air in the cold store. Both the structured mesh and unstructured mesh to cold store model were simulated. The simulation methods of airflow in a cold store between three-dimension (3D) technology and two-dimension (2D) technology were also discussed. The experiment was validated and proved that unstructured grid was in better agreement with the result of experiments and it was gotten that the three-dimension (3D) technology had a higher accuracy in simulation of airflow distribution. The airflow distribution in the vertical plane and horizontal plane in cold store were gotten, respectively.

Abstract: The unreasonable airflow distribution often occurs in the cold store. Some specific parameters of airflow in the cold store are difficult to obtain in the practical experiments. The unreasonable airflow causes quality decline and large energy consumption. In this paper, the airflow distributions in an empty commercial cold store and the cold store filled with products were studied by CFD and investigated using the 3D modeling method which combined SIMPLE calculation method and finite-volume method. Meshes of the fan were refined locally with the airflow near the walls was modified by applying the non-wall function. Through comparing the airflow distributions in the empty cold store and in the cold store filled with products, differences such as the lower margin velocity, the smaller width and the deviation of the main steam in the cold store filled with products were found.

Abstract: With the increasing strictness of emission regulations, development direction of future diesel engines is toward the high thermal efficiency and low emissions. Supercharging technology is an important means for improving output power of diesel engines. This paper deals with the study of the two-stage turbocharging system of the non-road diesel engine. Based on GT-Power software code, a digital model of 6112 diesel engine was established. The supercharged model was calibrated by using the original experimental data. Then, four types of digital models with different two-stage turbocharging systems were constructed. The best two-stage turbocharging system was determined through investigating the impacts of different options on the performance of diesel engines. It was indicated through the study that two-stage turbocharging system can substantially increase the air flowing into the cylinder which increases the potential of power density. At the same time HC and NOx emissions can reduce. Through this study, a theoretical basis and an important reference for adopting the two-stage turbocharging system of the 6112 diesel engine were provided.

Abstract: Abstract:A computational model is implemented to investigate hydraulic characteristics of turbulent flow through a 90 bending square duct. In the numerical solution the governing equations are first transformed by using boundary-fitted coordinate to map the physical domain to a uniform transformed space, subsequently discretized by finite-volume method and collocated grid system, and solved via SIMPLEC algorithm.The flow parameters at the control surface are obtained by momentum interpolation method. The modified k-ε turbulence model is applied to close the Reynolds stresses. The 3D hydraulic characteristics of flows in a bend square duct are computed, and the comparison between numerical results and experimental data shows a very good agreement.

Abstract: Applications based on CC (cloud computing) has the potential efficient and low-cost advantages, while there are the lack of computing power, the limited range of applications and the higher cost of BIM (Building Information Model) applications in the traditional desktop mode. According to BIM application features and the actual situation, the paper starts from the concept of CC and discusses the advantages of BIM applications using CC. The system framework, the key technologies and the implementation methods of the BIM application platform based on CC have been put forward on the basis of the above discussion.

Abstract: Combining the advantages of logical workflow nets and colored Petri nets, logical and colored workflow nets and collaborative logical and colored workflow nets are presented to facilitate the modeling of cooperative electronic commerce systems. The formal representation presented in this paper can not only describe the data objects, but also represent passing value indeterminacy and batch processing function of cooperative electronic commerce systems.

Abstract: The ground subsidence due to backfill mining is different from those caused by other mining methods. It’s practically important to analyze the influence of ground deformation due to backfill mining on the buildings above the ground accurately. An example of analysis of ground deformation on an iron mine in the east of Hebei was given in this paper. Then the reason why maximum subsidence angle becomes greater was analyzed by numerical simulation. The second derivative of subsidence curve was obtained by means of numerical method, and then the maximum curvature of ground deformation could be calculated. This quantitative analysis provided reference for safety assessment of buildings on the ground. The method was validated by the analysis on a real case. Comparing with other methods, this analysis method is relatively simple and more efficient.