A cycle bridge detection method, which uses a piezoresistive triaxial accelerometer, has been described innovatively. This method just uses eight resistors to form a cycle detection bridge, which can detect the signal...A cycle bridge detection method, which uses a piezoresistive triaxial accelerometer, has been described innovatively. This method just uses eight resistors to form a cycle detection bridge, which can detect the signal of the three directions for real time. It breaks the law of the ordinary independent Wheatstone bridge detection method, which uses at least 12 resistors and each four resistors connected as a Wheatstone bridge to detect the output signal from a specific direction. In order to verify the feasibility of this method, the modeling and simulating of the sensor structure have been conducted by ANSYS, then the dual cycle bridge detection method and independent Wheatstone bridge detection method are compared, the result shows that the former method can improve the sensitivity of the sensor effectively. The sensitivity of the x, y-axis used in the former method is two times that of the sensor used in the latter method, and the sensitivity of the z-axis is four times. At the same time, it can also reduce the cross-axis coupling degree of the sensor used in the dual cycle bridge detection method. In addition, a signal amplifier circuit and adder circuit have been provided, Finally, the test result of the ＂eight-beams/mass＂ triaxial accelerometer, which is based on the dual cycle bridge detection method and the related circuits, have been provided. The results of the test and the theoretical analysis are consistent, on the whole.展开更多
土体的微观结构对其宏观力学性质有着很大的影响,为了能更深入研究土体在循环荷载作用下的微观结构演化与其宏观力学特性之间的联系,研制了一种适用于工业显微CT(computerizedtomography)扫描的微型动三轴仪。该仪器主要由控制采集箱系...土体的微观结构对其宏观力学性质有着很大的影响,为了能更深入研究土体在循环荷载作用下的微观结构演化与其宏观力学特性之间的联系,研制了一种适用于工业显微CT(computerizedtomography)扫描的微型动三轴仪。该仪器主要由控制采集箱系统、主机系统、气水转换器组成。其具有体积较小、试样小型化(直径×高=10 mm×20 mm)、便于操作、兼容性强等优点,可在无需改装已有CT设备前提下对试样进行旋转扫描。以丰浦砂干砂样为材料,采用微型和常规动三轴仪进行了不同围压(50,100,200,300 k Pa)和循环荷载作用下的不固结不排水试验,并对测得的初始动弹性模量E_(0),动剪切模量G_(d),阻尼比l进行了对比分析。结果表明:微型动三轴仪测得的初始动弹性模量E_(0),动剪切模量G_(d),阻尼比λ与常规动三轴仪测得的结果基本相近。试验结果误差较小,验证了该仪器的可靠性。展开更多
基金Project supported by the National Science and Technology Cooperation Program of China(No.61011140351)the Special Fund of the National Natural Science Foundation of China(No.61127008)
文摘A cycle bridge detection method, which uses a piezoresistive triaxial accelerometer, has been described innovatively. This method just uses eight resistors to form a cycle detection bridge, which can detect the signal of the three directions for real time. It breaks the law of the ordinary independent Wheatstone bridge detection method, which uses at least 12 resistors and each four resistors connected as a Wheatstone bridge to detect the output signal from a specific direction. In order to verify the feasibility of this method, the modeling and simulating of the sensor structure have been conducted by ANSYS, then the dual cycle bridge detection method and independent Wheatstone bridge detection method are compared, the result shows that the former method can improve the sensitivity of the sensor effectively. The sensitivity of the x, y-axis used in the former method is two times that of the sensor used in the latter method, and the sensitivity of the z-axis is four times. At the same time, it can also reduce the cross-axis coupling degree of the sensor used in the dual cycle bridge detection method. In addition, a signal amplifier circuit and adder circuit have been provided, Finally, the test result of the ＂eight-beams/mass＂ triaxial accelerometer, which is based on the dual cycle bridge detection method and the related circuits, have been provided. The results of the test and the theoretical analysis are consistent, on the whole.
文摘土体的微观结构对其宏观力学性质有着很大的影响,为了能更深入研究土体在循环荷载作用下的微观结构演化与其宏观力学特性之间的联系,研制了一种适用于工业显微CT(computerizedtomography)扫描的微型动三轴仪。该仪器主要由控制采集箱系统、主机系统、气水转换器组成。其具有体积较小、试样小型化(直径×高=10 mm×20 mm)、便于操作、兼容性强等优点,可在无需改装已有CT设备前提下对试样进行旋转扫描。以丰浦砂干砂样为材料,采用微型和常规动三轴仪进行了不同围压(50,100,200,300 k Pa)和循环荷载作用下的不固结不排水试验,并对测得的初始动弹性模量E_(0),动剪切模量G_(d),阻尼比l进行了对比分析。结果表明:微型动三轴仪测得的初始动弹性模量E_(0),动剪切模量G_(d),阻尼比λ与常规动三轴仪测得的结果基本相近。试验结果误差较小,验证了该仪器的可靠性。
