Applied Mechanics and Materials Vols. 275-277

Abstract: Construction design, one of the oldest specialties in civil engineering, is a combination work of architectural design and structural analysis. By the development of computer technology, the idea of construction design has been revolutionary changed. This paper introduces a new construction design methodology considering both evolutionary structural optimization and 3D model printing technology. Instead of manual drawing and planning, computer-aided design (CAD) is the used to assist in the creation, modification, or analysis of an architectural design. Computer-aided design involves more than just drawing. In structural engineering area, by using the finite element analysis software (ABAQUS), evolutionary structural optimization (ESO) method can improve the design in defining shape, choosing material and calculating the tolerance of a construction. Finally, the computer designed digital model is made into a three dimensional solid object from the 3D model printer. The solid model can give a visualized view of the whole construction.

Abstract: Evaluation of liquefaction potential of soils is important in geotechnical earthquake engineering. Significant phenomena of gravelly soil liquefaction were reported in 2008 Wenchuan earthquake. Thus, further studies on the liquefaction potential of gravelly soil are needed. This paper investigates the potential of artificial neural networks-based approach to assess the liquefaction potential of gravelly soils form field data of dynamic penetration test. The success rates for occurrence and non-occurrence of liquefaction cases both are 100%. The study suggests that neural networks can successfully model the complex relationship between seismic parameters, soil parameters, and the liquefaction potential of gravelly soils.

Abstract: Three-dimensional geological model of open-pit is an information platform in the construction of digital mine, which plays a significant role in the engineering design and manufacturing management of open-pit. In the AutoCAD platform, take an open-pit for example, it is required to construct a geological database, to construct fault wire-frame model according to the ore body lines, to construct a terrain model according to the present situation map of stope and topographic contour map, to construct coal solid model according to the borehole data and interpolation points, and realize a visible display of a three-dimensional geological model for the open-pit; to construct a block model according to the coal & rock solid model, and add the attribute and assign to it, and then apply it to the calculation of stripping and mining quantities of open-pit. Compared with traditional calculation method, this method is simple in operation, which enhances its calculation speed and precision.

Abstract: When operating a 5-axis linear cutting command G01, the controller automatically inserts point data between two NC blocks in a linear distribution fashion, and then drives the cutter along these inserted points. If a simultaneous 5-axis machining is initiated, and CL data is directly transformed one-to-one into NC data, and then cutting is performed directly without having the 5-axis controller inserting any points between NC blocks, its processing path will deviate from the original plotted path. In fact, the processing path is no longer a straight line, but a curve line. This study proposes a method to increase CL interpolation points to automatically rectify the path deviation. The extent of research of this study comprises: (1) Transforming CL data into NC data (2) Programming tool orientations (3) Obtaining all CL interpolation points and their tool orientations (4) Generating NC data.

Abstract: In computer-aided design for moldings, automatic generation of side-cores is a crucial design task that has an influence on the entire mold structure and manufacturing cost. This paper proposes a synthetic approach for creating the side-cores of free-form NURBS surface models. Based on the geometric properties of entities, surfaces of undercut features which are molded for side-cores are identified. After determining the withdrawal directions for each group of undercut’s surface features, the number of side-cores is optimized. The heads and the bodies of side-cores are finally obtained through the combination of the Boolean operation and 3D oriented extrusion. The algorithm is efficiently for both protruded and indented portions of undercut features. A complex industrial part is used to demonstrate the performance and robustness of the proposed algorithm. Since the approach is generic in nature, it is easy to be applied to any complex geometry in 3D mold design.

Abstract: The starting energy dissipation of on-ramp system with open boundary condition is investigated by means of cellular automata simulations. We study the influence of the injection rate of on-ramp, the injection rate of main road and the removal rate of main road on the starting energy dissipation of each road. It is found that even though the injection rates neither of on-ramp nor main road have influence on the starting energy dissipation when critical values achieved, the removal rate of main road has a major impact on the starting energy dissipation of the system all along.

Abstract: In this paper, the robust state feedback guaranteed cost control problem for discrete-time systems with signal quantization is studied. A dynamic quantization control strategy is proposed with updating the quantizer’s parameter such that the system is asymptotically stable and the performance index is with a upper bound.

Abstract: To solve collaboration problem in multi-expert system, intelligent agent technology is used in multi-expert system.Firstly,by introducing a minimum-cost-based formal description of task decomposition,a new agent task decompositon model is presented.Secondly, heuristic algorithm for task decomposition is analyzed to solve communication among agents.For illustration, expert systems for oil-gas reservoir protection is utilized to verify the effectiveness of the method.The application of the expert system shows that based-minimum-cost task decompostion model is valid in agent task decomposition and heuristic algorithm for task decomposition can be used as communication among agents.As a result，the proposed cooperation mechanism based on agents can effectively solve the collaboration of experts in the multiple expert systems and improve the accuracy of inference.

Abstract: In this paper, high order consensus problem of multi-agent systems with non-identical unknown nonlinear dynamics following an unknown and nonlinear leader is investigated in networks with fixed and switching topologies. By parameterizations of unknown nonlinear dynamics of agents in the system, neighbor-based adaptive consensus algorithms are proposed by incorporating consensus errors in addition to relative position feedback. Base on algebraic graph theory, Lyapunov theory, Riccati inequalities and PE condition, analysis of stability and parameter convergence of the proposed algorithm are conducted. Finally, a simulation in switching networks is worked out to illustrate the effectiveness of the theoretical results.

Abstract: The core technique of flood forecast and pre-warning of a river basin is the numerical simulation of flood process in a complicated flood control system. According to the structural features, flood features, and flood process mechanism of a large and complicated flood control system, a 1D and 2D coupled numerical simulation model was established. The 1D model was used for the trunk river and main branches, and the 2D model was used for flood districts. The coupled 1D and 2D was used to simulate the flood regulation and process in rivers, lakes, flood districts, and floodways. A case study was conducted in the section from the Wangjiaba to Bengbu floodgates in the middle reach of the Huaihe River. The coupled model was employed to synchronously simulate the branch rivers and trunk flood of the river basin and to improve the accuracy of flood simulation, flood forecast, and regulation of the river basin. The parameters of the model for simulating the flood process of the Huaihe River Basin in 2003 were calculated and verified, and the flood process in 2007 was demonstrated. The simulated results show that the flood regulation and process can be accurately simulated by the proposed numerical model, and the accuracy requirements can be satisfied. Finally, the model was applied to the effect analysis of a four-grade emergency flood control plan in the Huaihe River Basin.