Papers by Author: Kai Xue

Abstract: A novel design method for stiffener layout of plate and shell structures is proposed in this paper. The method is inspired by the morphogenesis mechanism of dicotyledonous venation which is featured by hierarchy and functional adaptivity. It is expected that a optimal stiffener layout can be gradually achieved if the stiffeners extend by obeying a similar growth rule as the venation. Starting from the so called “seeds”, the stiffeners grow and branch off towards the direction that optimizes the structural performance. And the stiffeners with the minimum effectiveness to the structural performance are degenerated simultaneously. During the design process, the relative density of each element is treated as the design variable. The growth and degeneration of the stiffeners are determined by the nodal and elemental sensitivity numbers respectively. The design algorithm is programmed in Python and integrated with Abaqus software which is used as the FEA preprocessor and solver. To validate the effectiveness of the proposed method, it is applied to design the stiffener layouts of some typical structures with the objective of maximizing the overall stiffness with a volume constraint.

Abstract: An analysis method has been proposed for the vibration analysis of the Mindlin rectangular plates with general elastically boundary supports, in which the vibration displacements and the cross-sectional rotations of the mid-plane are sought as the linear combination of a double Fourier cosine series and auxiliary series functions. The use of these supplementary functions is to solve the potential discontinuity associated with the x-derivative and y-derivative of the original function along the four edges, so this method can be applied to get the exact solution. Finally the numerical results are presented to validate the correct of the method.

Abstract: t is high in efficiency to cut rectangular steel pipes with flame cutting mode compared with milling mode, and it is simple in processing equipment. When cutting the four arc angles of steel pipe, the steel pipe carries out the uniform rotational motion while cutting torch carries out plane two-dimensional motion, in order to achieve uniform motion in a straight line relative to the round arc angle of steel pipe. The rotation speed of steel pipe is proportional to the cutting speed. And the X component and Z component for the speed of cutting torch will respectively change according to the sine and cosine curves. The space geometrical relationship and motion relationship of round corner torch track and steel pipe corner are described by means of parametric equations. And the correctness of the algorithm in CNC rectangle pipe cutting machine has been verified.

Abstract: This paper proposes a kind of design and realization method of real time control system that based on the Windows real time extension module RTX, which can meet the requirement of six-freedom Stewart platform control system to the real time. The design of the control system was divided into real-time layer and non-real-time layer according to the requirements of various functions to the real-time, and the data communication was realized by means of inter-process communication mechanism. The analysis conclusion to experiments data indicates that the control system is stable in operation and good in real-time performance.

Abstract: A new reinforcement distribution design method inspired by venation configuration is discussed in the paper. Learned from dicotyledonous venation, venation growing algorithm is proposed, minimization of strain energy and shear stress determine growth direction of the mainveins and subveins respectively. Vectorial equilibrium equation is used to calculate vein widths and adjust the orientation of vein cells slightly. Sensitivity number is used to measure the change in strain energy and shear stress when a vein cell grows, necessary equations are derived for bending Kirchhoffs plate. Several examples are design for venation-like rib distribution. The resultant rib layout by VGA is applicable and effective.

Abstract: The rectangular coordinate CNC pipe profile cutting & welding integrative equipment is researched for the requirements of cutting and automatic welding of complicated butt pipes intersection lines. The mechanical structure of the equipment is that the workpiece is placed onto the supports, the chuck is carried out with limitless rotary movement. The main body for holding cutting torch and welding torch is adopted with cantilever arm traveling structure, and is controlled by six-axis digital AC servo system. The CNC system is developed based on Windows operation system, and it is a kind of pure software open architecture. RTX real-time extension technology is adopted to realize the high real-time requirement in motion control. The minimum deviation method is used to realize the interpolation algorithm of curve which describes the space track of intersection line. The equipment has realized the pipe cutting for blanking and welding for assembling at the same working position, and can meet the requirements for automatic pipe processing technology.

Abstract: Based on a classical model of the noise and vibration control, the dynamic modal of the turntable shafting of the typical half shaft system (shaft-bearing-framework) is established. The transmission matrix method is applied to analyze the dynamical model. The power flow expression of the subsystem is derived from theoretical analysis using the sub-structure mobility method. The bearing system uses Lim model. The technology lays foundation on the vibration property of the turntable structure for the further research.

Abstract: An engineering computational method of major loads in three-axis motion simulator is presented. Simulation calculation of the motor output torque has been completed when three frames individually swinging, and individually rotating at a constant speed; the motor coupling torque was also computed when synchronously swinging, and synchronously rotating at a constant speed. The test experiment has been finished. According to the comparison of results from the simulation, the experiment and the engineering computation, a conclusion is drawn that the simulation results in ADAMS are helpful for selection of driving motor in design stage, because the engineering computation results without taken the coupling impact between three frames into consideration are not accurate where the coupling impact of torque in three frames leads to an increase in motor output torque when the three frames rotating synchronously.

Abstract: This paper concerns biomimetic exploration of the leaf rib layout problem. Biological venation of organisms is observed to be similar to reinforced plate/shell systems. Similarity analysis makes it clear that dicotyledonous leaves are an ideal research subject. In this paper, global and local regularities are summarized and existing theories on venation morphogenesis are discussed and compared. An energy hypothesis is proposed to cater for interdisciplinary applications. A venation growing model was then used to construct a two-dimensional reinforcement layout model. The biomechanical expressions developed can be an alternative to describe rib-in-plate or fibre-in-composite materials.

Abstract: GPS attitude tracking system on the ship is a servo mechanism which could be used for counteracting the effects of the ship’s pitch and roll. But the attitude measurement precision of ship is more important to the tracking precision of the servo mechanism. As one of the major error sources, the noises of GPS attitude measurement bring out the steady tracking error of the tracking servo mechanism. To reduce the steady error due to the noise, the threshold noise removing method of wavelet is used to eliminate the noise. And the better result with the meaning of standard deviation and the better visual effects could be gotten by using the method. The signals of the processed high frequency and the retained low frequency could be reconstructed with the original signals. Therefore, the signals after noise removing could be obtained. The threshold noise removing method of wavelet used to remove the noise of GPS attitude information in the paper is of great value in practice.