带式输送机在采用固定拉紧装置时胶带的加速度响应值特性研究

文中给出了带式输送机在采用固定拉紧装置时胶带弹性振动方程的加速度解 ,研究了在采用矩形、梯形、三角形、正弦形、抛物线形加速度时胶带的加速度响应值特性 ,给出了限制和消除带式输送机弹性振动的设计方法 ,提出了最佳的软起动和软制动控制曲线 ,可用于理论研究与工程设计。

基于人工合成波的电信设备抗震试验响应分析

进行电信设备人工合成波地震试验时,对被测设备进行有关参量的响应分析,是对波形试验的技术性完善。通过响应监测和分析获取的信息,对于被测设备的抗震结构优化具有很高的参考价值。该文结合具体的测试案例,提出了人工合成波地震试验时应对被测样品进行监测的响应分量,论述了扭矩、加速度响应值和形变量等三个特性参数的重要性,并探讨了具体的分析方法。文章并指出,响应监测因子有待进一步丰富。

基于深度置信网络的工字钢梁损伤识别方法

研究目的:工字钢梁作为一种重要的受力结构,在建筑结构、桥梁支架、轨道交通、仓储厂房等领域应用广泛。由于其在服役期间极易受到外部荷载、自然环境、材料性质等影响而发生严重的损伤,危害结构的耐久性和安全性,因此有必要采取相应的措施及时发现工字钢梁的损伤状况。基于深度置信网络的工字钢梁损伤识别方法,提取结构发生振动时的竖向加速度响应值作为损伤指标,通过深度置信网络对损伤指标的特征分析,识别结构的损伤位置和损伤程度。研究结论:(1)该方法在损伤位置和损伤程度方面的识别准确率均在90%以上,且随着噪声程度不断提高,识别准确率能够保持稳定的水平,抗噪性能好;(2)SVM支持向量机在损伤位置的识别准确率低于20%,BP神经网络在损伤程度的识别准确率低于70%,随着噪声程度不断提高,两种传统的方法识别准确率不能保持稳定的水平,识别能力差;(3)本文所提出的基于深度置信网络的损伤识别方法具有一定的可行性,在实际工程应用中可研究性较强,具有一定的研究前景。

灵巧弹药缓冲减震性能试验研究

为了有效解决高性能灵巧弹药的防护包装和缓冲减震问题,文中采用了不同密度、不同结构的泡沫塑料,在运输、振动、冲击和跌落环境条件下,有针对性地进行了高性能灵巧弹药在非缓冲或缓冲状态下作用在产品上的加速度响应值试验研究。研究结果表明,弹药的体积密度与加速度响应值在相同的环境试验条件下,体积密度大的产品加速度响应值小,体积密度小的产品加速度响应值大。

Numerical analysis on seismic behavior of railway earth embankment: A case study

A numerical case study on the seismic behavior of embankment was carried out based on a prototype of earth embankment in Yun-Gui Railway （from Kunming City to Nanning City） in southwest of China. A full-scale model of earth embankment was established by means of numerical simulation with FLAC3D code. The numerical results were verified by shaking table test. The seismic behaviors of earth embankment were studied, including the horizontal acceleration response, the vertical acceleration response, the dynamic displacement response, and the block state of earth embankment. Results show that the acceleration magnification near the embankment slope is larger than that in internal earth embankment body. With the increase of input peak acceleration, the horizontal acceleration magnification presents a decreasing trend. The horizontal acceleration response at the top of embankment is more sensitive to the intensity of ground motion than that at the bottom of cmbankment. The embankment presents an obvious nonlinear-plastic characteristic when the input horizontal peak acceleration is larger than 0.3 g. The maximum residual deformation occurs in the middle of embankment slope surface instead of at the top of embankment. The upper part of embankment experiences tension failure without shear failure, and area at mainly presents shear failure under the earthquake loading. surface of earth embankment. the bottom of embankment around the symmetry-axis of embankment The tension failure and shear failure repeatedly occur along the slope

Fundamental Characteristics of Reduction System for Seismic Response using Friction Force

A new device of reduction for seismic response using friction force was developed. In this paper, fundamental characteristics of reduction system for seismic response using this device were investigated by excitation experiment using artificial seismic waves. The peak acceleration amplitude on this system has decreased to about 50-90% over the input waves. Although a spectral peak around the frequency of 0.5Hz that is the natural period of this system was identified, the value of a spectral peak was decreased using bearings with the high friction force. This device is useful for reduction of seismic response.

基于SDAE的连续梁桥损伤识别方法研究

基于动力检测的桥梁损伤识别常采用BP神经网络、SVM等方法,这些方法学习时间长,计算过程复杂,并与损伤指标的选取密切相关,损伤指标的获取难度、敏感性对识别效果有着至关重要的作用。为实时判断桥梁结构状态,利用云计算、大数据深度学习计算能力大幅提升的优势,提出一种基于SDAE(stacked DAE,堆叠去噪自编码器)网络的连续梁桥结构损伤识别定位方法。以两等跨混凝土连续梁桥为对象,直接采集结构的加速度响应值,通过堆叠去噪自编码器识别不同噪声环境下单损伤和多损伤位置,从识别准确率、抗噪性能方面与现有的机器学习方法BP神经网络、SVM支持向量机进行比较,验证其可靠性和适用性。