相关实验视频
Updated: May 25, 2025

08:12
Experimental Methods to Study Human Postural Control
Published on: September 11, 2019
9.4K
对最基本的时间域输入输出系统识别方法进行数值和实验研究,用于灵活结构的正常模态分析
Şefika İpek Lök1, Carmine Maria Pappalardo2, Rosario La Regina2
1Defense Industries Research and Development Institute, Scientific and Technological Research Council of Türkiye (TÜBİTAK), 06105 Ankara, Türkiye.
Sensors (Basel, Switzerland)
|February 26, 2025
概括
本研究比较了用于结构模式分析的时间域系统识别方法. 它引入了改进的缓冲矩阵估计,并分析了使用振动测试装置对灵活结构的模型减速技术.
科学领域:
- 结构动态和控制结构动态和控制
- 系统识别和信号处理
背景情况:
- 实验模式分析对于理解结构性行为至关重要.
- 时间域系统识别方法为分析动态系统提供了强大的方法.
- 由于测量噪声,准确估计模态参数,特别是减噪,具有挑战性.
研究的目的:
- 进行对结构系统的主要时间域系统识别方法的比较分析.
- 调查和改进质量,刚性和阻尼 (MSD) 矩阵的估计.
- 在灵活结构的实验模态分析中评估不同方法的性能.
主要方法:
- 自动回归异源 (ARX) 方法
- 国家空间估算 (SSEST) 方法.
- 小空间状态空间系统识别的数值算法 (N4SID)
- 具有观察者/卡尔曼波器识别 (OKID) 的自身系统实现算法 (ERA).
- 转移函数ESTimation (TFEST) 的使用方法
- 相对缓冲系数 (PDC) 识别方法的方法.
- 模型订单减少 (MOR) 使用平衡切割方法 (BTM)
主要成果:
- 识别的模型被用来估计MSD矩阵.
- 比例减缓系数 (PDC) 方法提高了减缓矩阵识别的准确性.
- 对各种方法的性能分析是在振动测试装置上进行的.
结论:
- 该研究提供了用于结构模式分析的时间域系统识别技术的全面比较.
- 在杂的环境中,PDC方法提供了一个可行的解决方案,用于增强声估计.
- 这些发现通过来自代表性结构系统的实验数据来验证.
相关概念视频
Dynamic Modulus of Elasticity of Concrete
250
The dynamic modulus of elasticity assesses how a concrete structure deforms under impact or dynamic loads. It is typically higher than the static modulus of elasticity, measured under slow, steady loading conditions.
The sonic test is a common method to determine the dynamic modulus. In this test, a concrete beam, sized either 6 x 6 x 30 inches or 4 x 4 x 20 inches, is clamped at its center. Vibrations are initiated at one end of the beam by an electromagnetic exciter unit powered by...
The sonic test is a common method to determine the dynamic modulus. In this test, a concrete beam, sized either 6 x 6 x 30 inches or 4 x 4 x 20 inches, is clamped at its center. Vibrations are initiated at one end of the beam by an electromagnetic exciter unit powered by...
250
Linear Approximation in Time Domain
59
Nonlinear systems often require sophisticated approaches for accurate modeling and analysis, with state-space representation being particularly effective. This method is especially useful for systems where variables and parameters vary with time or operating conditions, such as in a simple pendulum or a translational mechanical system with nonlinear springs.
For a simple pendulum with a mass evenly distributed along its length and the center of mass located at half the pendulum's length,...
For a simple pendulum with a mass evenly distributed along its length and the center of mass located at half the pendulum's length,...
59
Bending of Members Made of Several Materials
137
In analyzing a structural member composed of two different materials with identical cross-sectional areas, it is crucial to understand how their distinct elastic properties affect the member's response under load. The analysis involves assessing stress and strain distributions using the transformed section concept, which accounts for variations in material properties.
Hooke's Law determines stress in each material, stating that stress is proportional to strain but varies due to each...
Hooke's Law determines stress in each material, stating that stress is proportional to strain but varies due to each...
137
Shear and Bending Moment Diagram: Problem Solving
1.2K
When analyzing a beam supporting concentrated loads and a distributed load, drawing the shear and bending moment diagrams is essential. These diagrams help understand the internal forces and moments acting on the beam, which is crucial for designing safe and efficient structures. Follow these steps to create the shear and bending moment diagrams:
Draw a Free-Body Diagram: Start by drawing a free-body diagram of the entire beam, including the concentrated loads, distributed load, and reaction...
Draw a Free-Body Diagram: Start by drawing a free-body diagram of the entire beam, including the concentrated loads, distributed load, and reaction...
1.2K
Second Order systems II
80
In an underdamped second-order system, where the damping ratio ζ is between 0 and 1, a unit-step input results in a transfer function that, when transformed using the inverse Laplace method, reveals the output response. The output exhibits a damped sinusoidal oscillation, and the difference between the input and output is termed the error signal. This error signal also demonstrates damped oscillatory behavior. Eventually, as the system reaches a steady state, the error diminishes to zero.
80
Classification of Systems-II
133
Continuous-time systems have continuous input and output signals, with time measured continuously. These systems are generally defined by differential or algebraic equations. For instance, in an RC circuit, the relationship between input and output voltage is expressed through a differential equation derived from Ohm's law and the capacitor relation,
133

