Applied Mechanics and Materials Vol. 274

Abstract: Papermaking waste liquid instead of water to prepare coal water slurry, which aim is turning waste into treasure. Not only can the waste fundamentally eliminate environment pollution, but also saving a lot of water resources. Because the waste contains large amounts of sodium, which is one of the main reasons of heating surface slagging of boiler. So it is necessary to improve and increase the soot blowing device of heating surface of boiler.

Abstract: Based on the analysis of the absorption spectrum of dried object and the radiation spectrum of heater, the concept of Matching Absorption Degree in Whole Wavelength Region (MADWWR) and its design optimization method are put forward. The corresponding mathematical model is established. Taking soft-base coat drying for example, design optimization of MADWWR is carried out in different temperatures. The optimal values of MADWWR and surface temperature of heater are obtained. The effectiveness of the results is verified by the engineering example. The calculation method and the corresponding calculation program of optimal matching degree are universal, which can provide useful guidelines for the energy-saving design of infrared heating and drying.

Abstract: Portable wheel loads measure plate is force sensor based on strain measure and it can bear multidimensional force simultaneously. It is able to recognize radial wheel load through decoupling. Signal conditioning of the sensor will affect the measure accuracy. There are many strain-gauges in the plate. So the signal of measure plate will include CM noise, thermal noise and high shift. The signal conditioning aimed at these disadvantages should be high gain, high accuracy, low noise, low shift, high CMRR. Multisim is adopted to analyze the signal conditioning including strain measure amplifying circuit, instrumentation amplifier AD620, operational amplifier OP07. It is turned out to be low linear distortion and is able to satisfy practical application through the experiment.

Abstract: The dynamic simulation analysis method is adopted to investigate the dynamic damping characteristics of lathe tool with large length to diameter (L/D) ratio. The multi flexible body dynamical simulation model of dynamical damping lathe tool with large length to diameter ratio is built up according to the actual experiment lathe by using the software ADAMS and ANSYS. Simulation analysis of the multi flexible body dynamical model which has been optimized shows that the system damping performance is improved greatly. On this basis the relationship of rubber bush, mass body and vibration absorption cavity is discussed. And the result of the discussion indicates that the shape of rubber bush should be confirmed by repeatedly simulating the model.

Abstract: In order to research the possibility of Motor Current Signature Analysis (MCSA) applied to fault diagnosis of double fed wind turbine generator system and overcome the defect of sensor stalled installed inconveniently with regular vibration inspection method constructs a simulation model of double fed wind turbine generator with SIMULINK, which uses PWM module for stator excitation and the signal of rotating speed and torque of external dynamic changes to simulate the fault of wind turbine motor transmission system, and then verifying the accuracy of fault features of stator current when generator system has fault by emulating and analyzing the response process of signal in the stator current of generator with different situations.

Abstract: By modeling ship motion using PM wave spectrum and strip theory, and modeling vehicle as rigid chassis and flexible tire, the dynamics equation of ship and vehicle multi-body system is developed using Lagrange equation. The numerical solution of equation shows the forces between tire and deck contact are impacted by ship motion. To compare the possibility of tip over around different axes, a Moment-Height Stability (MHS) measure method is used to calculate the stability of vehicle on the deck. The MHS result shows compartments of the instability around each edge, which is a good supplement to the tire force method.

Abstract: The effects of masonry infills on the seismic performance of a multi-story steel frame building were investigated through nonlinear static and dynamic analyses. Three variants of masonry infills, aimed at simulating weak, intermediate and strong infill panels, and the presence of masonry openings were considered in the numerical analyses. Strong masonry infills significantly contributed to the lateral stiffness and load resistance of the steel structure, but a sudden decrease of strength was observed after the failure of infills. This phenomenon was less evident in presence of openings. The results of the nonlinear dynamic analyses confirmed the satisfactory performance of masonry infilled steel structures under the design earthquake intensity. The presence and the mechanical properties of the infills affected the distribution of damage throughout the structure. The maximum inter-story drift occurred at the third level for the bare structure, whereas in the structures infilled by strong masonry panels the maximum inter-story drift was registered at the first level.

Abstract: An innovative dissipative (INERD Pin) connection system, which was previously developed for seismic resistant X-braced steel frames, was applied to retrofit existing precast industrial buildings designed only for gravity loads. Nonlinear dynamic analyses were carried out and the effectiveness of the dissipative connection system was evaluated. The INERD Pin connection system increased both the deformation capacity and the stiffness of the buildings, reducing damage of the structural elements. In case of low seismic actions, the INERD Pin connection system especially enhanced the stiffness of the structure, causing only small reductions of column rotations and top displacements. In case of severe seismic actions, the addition of the dissipative connections showed all its effectiveness particularly for low rotation capacity at column base, increasing the energy dissipation capacity and reducing the displacements of the structure. The results of the numerical investigations demonstrated the possibility to reduce the seismic vulnerability of existing precast buildings by means of dissipative connection systems.

Abstract: NURBS curve fitting is used for tool path planning for sculptured surface NC machining. The cutter location data is parameterized by equal chord arc length parameterization, and Centripetal Parameterization is improved. It is not only more approach to curves nature equation in theory, but also closer to the interpolated curves in actual fitting. It is directly to reflect the curvature of curves of cutter location in NC machining.

Abstract: With heavy hydrostatic bearing as the research object, establish oil film viscosity-temperature equation. Adopt finite volume method, respectively calculates the oil film temperature field under different rotate velocity in Invariant viscosity and variable viscosity, revealing the oil film temperature arise influence rule of hydrostatic bearing on the viscosity and rotate velocity. The results show that the viscosity and rotate velocity have a great influence on the hydrostatic bearing oil film temperature rise, but the effect regularity varied. The calculated results that provide a theoretical basis for the hydrostatic bearing structure design and bearing deformation calculation, and have very important significance on improve the reliability and precision of the whole machine tools.