Advanced Materials Research Vols. 1025-1026

Abstract: The purpose of this research is to investigate the mechanical property of catheter, which is made of soft nylon resin and is reinforced with thin stainless wires called braid. In this paper, the relation between the deformation speed and the buckling phenomenon is examined by using the catheters which have a viscoelastic property. If we image the actual usage, the different types of several loads such as torsion and bending are applied simultaneously to the catheter. Thus, it is expected that the buckling phenomenon of the catheter will be more complicated. In this study, as the initial step to reveal the buckling behavior under combined loading state, the buckling tests under combined loading of compression and torsion are carried out under the proportional deformation path by changing the speed of axial displacement and the torsional angle. And then, the effect of the stress relaxation on the occurrence region of buckling under combined loading state is revealed in this paper.

Abstract: This paper is principally performed to survey end-plate connection are described in the next part based on ideal limit states. The determination of end-plate based on the full plastic strength of the steel beam in accordance with 2001 AISC-LRFD manual and AISC/ANSI 358-05 Specifications. The bolted connections considered herein were performed to include the end-plate component of moment connections. This study is intended to investigate economic design for end-plate connections. In addition, the proposed end-plate model is evaluated by comparing the required factored bolt strength. The end-plates using 8 high strength bolts with wider gages demonstrated this design. The equations belonging to the step-by-step design procedure are described based on complete proving of design. Finally, new design methodology is applied to end-plate connections suggested in this study.

Abstract: Based on the characteristics of the geometric control method during the construction of cable-stayed bridge, the key goal to complete the bridge is to ensure that the non-stress dimensions and profile of every component is constant. Because one of the key points to complete the cable-stayed bridge is to ensure that the non-stress length of the closure segments is constant, it is necessary to adjust the relative position of the final closure by the geometric closure method of incremental launching construction to satisfy the requirement of the non-stress length of the closure segments. Aimed at the critical technical problems existing in incremental launching construction process, taking Jiashao bridge as the research subject, the analysis of the incremental launching plan and the local stress of pushing bracket and bearing block are carried out. The research will provide scientific basis for the feasibility of geometric control incremental launching construction method and it will guarantee the smoothly incremental launching construction.

Abstract: The application of tuned mass dampers (TMDs) to offshore wind turbines has a huge potential to suppress the large vibration responses of these systems. Control module of TMDs is added into the wind turbine structural dynamics simulation code FAST and fully coupled aero-hydro-TMD-structural dynamics model of the 5MW Barge-type floating wind turbine by National Renewable Energy Laboratory (NREL) is established. A multi-parameter optimization study is performed to determine the optimal parameters of a fore-aft TMD system in the Barge-type model. The wind turbine model equipped with the optimal TMD is then simulated under five typical load conditions and the performance of the new system is evaluated. The results show that longitudinal loads at tower base and deflections at tower top reductions of up to 50% and longitudinal loads at blade root and deflections at blade tip reductions of up to 40% are achieved, which indicates that the optimal TMD can be used to suppress the vibration response of offshore wind turbines and also demonstrates the potential for TMD structural control approaches.

Abstract: The paper shows a simulation of the motion of simple planar robot, consisting of two links and kinematic drives on SimulationX. Model of robot takes into account the characteristics of the servomotors. The simulation results of robot motion can be obtained in a convenient graphical form for subsequent analysis. The model can be used in laboratory work by students in the universities of Kazakhstan.

Abstract: The main objectives of this paper was to investigate the cyclic performance of splice connection in weak-axis column-tree connections with the formation of plastic hinge assumed at splice connection and provide some design recommendations. By reducing the cross-sectional area of the splice plates, the splice connection in this test are designed as a weaken component to utilize the ductility capacity and energy dissipation. The results showed that it could develop the plastic rotation capacity in the beam splice connection and portion in the link beam but not increase the energy dissipation capacity during the same story drift ratio.

Abstract: The objective of this paper is to research seismic performance of the weak-axis column-tree connections. For this purpose, two specimens CTY600 and CTY900 were fabricated and tested in this experiment. From the test results, the CTY specimen successfully achieved a 5% rad story drift ratio without brittle fracture and the total plastic rotation reached over 0.04rad.

Abstract: In order to study the effects of the supporting beams with different forms of section on the aerodynamic characteristics of car models. Model supporting beams with three different forms of section were designed based on standard MIRA model. The commercial CFD software - Ansys Fluent was used to simulate the three-dimensional flow field around the standard MIRA model installed with three different kinds of supporting beams. With comparisons between the drag coefficients, pressure distributions and velocity distributions around the wheels with the different supporting beams, the reasons for the differences in aerodynamics are analyzed and advices were given for helping choosing the supporting beam with minimal disturbance to reduce the correction error.

Abstract: Aeroelastic wind tunnel tests were conducted on conventional and tapered super-tall buildings to investigate the effect of the taper on the aeroelastic behavior for various wind directions and normalized velocities, with a focus on the maximum tip displacement. The natural frequencies and damping ratios were adjusted by means of the spring stiffness and magnetic field at the bottom of the test models. The displacements at the bottom of the test models were measured and transformed to tip displacements. The results showed that the taper suppressed the maximum tip displacement in both the X and Y directions, although the suppression was greater in the Y direction, especially for small wind directions. Moreover, the variations of the maximum tip displacement in the X direction with the wind direction and normalized velocity were small.

Abstract: The results of wind tunnel experiments were used to conduct time history analyses of three conventional square cross-section tall buildings with different structural systems. The primary purpose of the study was the direct comparison of the effects of the wind loads on the steel tall buildings. Time history analyses were conducted by applying local wind forces to the center of each floor. The results showed that, although the bending moments in the ground-level column on the two principal axes were different, the peak normal stresses were almost the same regardless of the structural systems. Similar observations were made regarding the tip displacements. Furthermore, analyses for the various loading conditions revealed that the contribution of the bending moment in the across-wind direction was the largest, followed by that in the along-wind direction. The ratio of the peak normal stresses for different loading conditions were observed to be almost the same regardless of the structural systems.