Papers by Author: Fu Zhao

Abstract: The time-dependent reliability model of Mechanical Component is influenced by many parameters such as stress, load, strength, strength degeneration and lifetime index. This paper builds the time-dependent reliability model when life is measured by the loading numbers. The variety law of mechanical component’s reliability with the lifetime is derived from the built model and simulation of link rod in needle bar mechanism used in the sewing machine. The result shows that the time-dependent reliability model is effective and the reliability of component decreases obviously with the loading numbers when the strength degeneration is considered.

Abstract: The time-dependent reliability model of Mechanical Component is influenced by many parameters such as stress, load, strength, strength degeneration and lifetime index. This paper builds the time-dependent reliability model when life is measured by the loading numbers. The variety law of mechanical component’s reliability with the lifetime is derived from the built model and simulation of tooth carrier in feed mechanism used in the sewing machine. The result shows that the time-dependent reliability model is effective and the reliability of component decreases obviously with the loading numbers when the strength degeneration is considered.

Abstract: As an important part of the vertical axis wind turbine, the support structure should have high strength and stiffness. This article adopts finite element method to model a kind of tower structure of the vertical axis wind turbine and carry out static and modal analysis. The static and dynamic characteristic results of tower in this paper provide reference for optimization design the support structure of wind turbine further.

Abstract: It is very significant for the vertical axis wind turbine to design the best support structure with high strength and stiffness. This paper discusses modeling a kind of tube tower structure of the vertical axis wind turbine and carries out static and modal analysis based on the finite element method. The static and modal characteristic of tube tower such as stress, strain and mode shapes are obtained accurately which can provide basis to optimal design the support structure for vertical axis wind turbine.

Abstract: Micro-actuator is the key device for the MEMS to perform physical functions. According to a kind of bimorph thermal actuator, this article presents an optimum design method to improve the sensitivity of MEMS actuator. Based on thermal analysis of software ANSYS, the thermal displacement and distribution of temperature field can be obtained clearly. Then a series of reasonable parameters are determined by optimum calculation. The simulation comparison analyses including thermal displacement, stress distribution and fatigue life are carried out to demonstrate that the sensitivity of the optimized structure has been improved effectively by the presented optimization method.

Abstract: The structure of chemical sensor has great influence on the performance of the sensor. This article studies on the relationship between the structure parameter and the mechanical characteristics of the sensor. The original resonance frequency and modes shape of the structure are obtained by the finite element analysis. Then a series of simulation comparison analyses are carried out to verify that the performance of modified sensor structure for food safety detection is improved greatly, which provides a good guide for the design of MEMS chemical sensor further.

Abstract: Uncooled infrared bolometer arrays have become mainstream low-cost thermal detector used in applications such as firefighting, security and surveillance, and environment temperature control for food operation. In order to resolve the pixel structure’s stress problem of microbolometer, this paper adopts finite element analysis method to model and analyze the mechanical properties of pixel structure. Several results of the stress and displacement are presented and the influence of structure optimization on the stress is also analyzed quantitatively. The research provides a good foundation and mechanics reference for mechanical design of uncooled microbolometer.

Abstract: In order to improve the sensitivity of MEMS temperature sensor, this paper proposes an efficient and robust structural optimum design method for the sensor structure. Based on thermal analysis of software ANSYS, the thermal deformation and distribution of temperature field can be obtained clearly. A predictive model for thermal deformation is established using artificial neural network and the sample for neural network model is designed by using orthogonal experimental method. In the model, the structure parameters of sensor are treated as design variables and the objective is to obtain the maximum deformation. Optimization of structure parameters for sensor was conducted by introducing artificial neural network prediction models into genetic algorithm. The results indicate that the optimization method based on artificial neural network and the genetic algorithm is feasible for improve the sensitivity of chemical sensor.

Abstract: With the three-dimensional computational fluid dynamics method, the airflow effects over the huge telescope assemble is investigated in this article. The distributing of velocity field and natural convection are studied by modeling and simulating the turbulent airflow of the huge telescope. Numerical simulations show the best observation direction is the 90o angle between the main optics axis and the horizontal line in which the air velocity distribution is the least. And the air temperature distribution and uniformity around the telescope are also provided by simulation.

Abstract: This paper focuses on the structural optimization of chemical sensor support for food safety detection. The mechanical characteristic of chemical sensor support is influenced greatly by its structural parameters. Aiming at improving dynamic stiffness of the support, the modal analysis is implemented with the dynamic theory and the finite element analysis. And a group of rational structure parameters are determined through the optimum calculation. The validity simulation of the optimization is verified by the analyses of the random vibration and harmonic response. The results demonstrate that the performance of the support of the chemical sensor applied for the food detection is enhanced greatly by the presented optimization method here.