High precision videogrammetric technique for structural dynamic response measurement

2005 ◽  
Author(s):  
Chih-Chen Chang ◽  
Yunfeng Ji
Keyword(s):  
Dynamic Response ◽  
High Precision ◽  
Response Measurement ◽  
Structural Dynamic

scholarly journals In-Situ Dynamic Response Measurement for Damage Quantification of 3D Printed ABS Cantilever Beam under Thermomechanical Load

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2079 ◽  
Author(s):  
Hamzah Baqasah ◽  
Feiyang He ◽  
Behzad A. Zai ◽  
Muhammad Asif ◽  
Kamran A. Khan ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Crack Propagation ◽  
Crack Depth ◽  
Dynamic Loads ◽  
Laser Vibrometer ◽  
Response Measurement ◽  
Structural Dynamic ◽  
Fused Deposition ◽  
And Behavior

Acrylonitrile butadiene styrene (ABS) offers good mechanical properties and is effective in use to make polymeric structures for industrial applications. It is one of the most common raw material used for printing structures with fused deposition modeling (FDM). However, most of its properties and behavior are known under quasi-static loading conditions. These are suitable to design ABS structures for applications that are operated under static or dead loads. Still, comprehensive research is required to determine the properties and behavior of ABS structures under dynamic loads, especially in the presence of temperature more than the ambient. The presented research was an effort mainly to provide any evidence about the structural behavior and damage resistance of ABS material if operated under dynamic load conditions coupled with relatively high-temperature values. A non-prismatic fixed-free cantilever ABS beam was used in this study. The beam specimens were manufactured with a 3D printer based on FDM. A total of 190 specimens were tested with a combination of different temperatures, initial seeded damage or crack, and crack location values. The structural dynamic response, crack propagation, crack depth quantification, and their changes due to applied temperature were investigated by using analytical, numerical, and experimental approaches. In experiments, a combination of the modal exciter and heat mats was used to apply the dynamic loads on the beam structure with different temperature values. The response measurement and crack propagation behavior were monitored with the instrumentation, including a 200× microscope, accelerometer, and a laser vibrometer. The obtained findings could be used as an in-situ damage assessment tool to predict crack depth in an ABS beam as a function of dynamic response and applied temperature.

Probabilistic analyses of structural dynamic response with modified Kriging-based moving extremum framework

2021 ◽  
Vol 125 ◽  
pp. 105398
Author(s):  
Cheng Lu ◽  
Cheng-Wei Fei ◽  
Yun-Wen Feng ◽  
Yong-Jun Zhao ◽  
Xiao-Wei Dong ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Structural Dynamic

Theoretical and Numerical Analysis on the Seismic Response of Underground Structures in Existence of Isolators

2011 ◽  
Vol 368-373 ◽  
pp. 710-714
Author(s):  
Jin Chun Liu ◽  
Yi Huan
Keyword(s):  
Dynamic Response ◽  
Analytical Procedure ◽  
Axial Loading ◽  
Seismic Loading ◽  
Underground Structures ◽  
Structural Dynamic ◽  
Metro Station ◽  
Single Degree Of Freedom ◽  
Theoretical And Numerical Analysis ◽  
Elastically Supported

In this paper, an analytical method of the beam with springs and dampers fixed at the ends was proposed based on equivalent single degree of freedom (SDOF) system and secondary Lagrange’s dynamic equations, in order to develop a new effective method to enhance the aseismic capability of underground structures. The dynamic response of elastically supported and damply supported beams subjected to both seismic loading and static axial loading was analyzed by the proposed analytical procedure. The theoretical results were validated by the numerical simulation. In order to further investigate the effects of springs and dampers fixed at the ends of the columns in nonlinear response situation, the 3D nonlinear seismic responses of the Dakai metro station structure with and without the isolators were analyzed by ABAQUS respectively. It is demonstrated that: (1) the proposed analytical procedure can predict the dynamic response of beams with elastic and damper supports subjected to both seismic loading and axial loading. (2) Setting isolators at the supports of the column could enhance the aseismic capability of the structure effectively. (3) The axial static loading induced by the gravity of the soil and structure provide the constraint on the column, and therefore could not be neglected in the structural dynamic analysis.

Dynamics Analysis of Refrigeration Compressor Based on Finite Element and Experimental Modes

2012 ◽  
Vol 499 ◽  
pp. 238-242
Author(s):  
Li Zhang ◽  
Hong Wu ◽  
Yan Jue Gong ◽  
Shuo Zhang
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Modal Analysis ◽  
Natural Frequency ◽  
High Precision ◽  
3D Model ◽  
Finite Element Models ◽  
Dynamics Analysis ◽  
Response Characteristics ◽  
Dynamic Response Characteristics

Based on the 3D model of refrigeration's compressor by Pro/E software, the analyses of theoretical and experimental mode are carried out in this paper. The results show that the finite element models of compressor have high precision dynamic response characteristics and the natural frequency of the compressor, based on experimental modal analysis, can be accurately obtained, which will contribute to further dynamic designs of mechanical structures.

scholarly journals Monitoring the structural dynamic response of a masonry tower: comparing classical and time-frequency analyses

2012 ◽  
Vol 10 (4) ◽  
pp. 1221-1235 ◽  
Author(s):  
Rocco Ditommaso ◽  
Marco Mucciarelli ◽  
Stefano Parolai ◽  
Matteo Picozzi
Keyword(s):  
Dynamic Response ◽  
Structural Dynamic ◽  
Time Frequency ◽  
Masonry Tower

scholarly journals COMMON CROSSING CONDITION MONITORING WITH ON BOARD INERTIAL MEASUREMENTS

2019 ◽  
Vol 59 (4) ◽  
pp. 423-434 ◽  
Author(s):  
Mykola Sysyn ◽  
Olga Nabochenko ◽  
Ulf Gerber ◽  
Vitalii Kovalchuk ◽  
Oleksiy Petrenko
Keyword(s):  
Dynamic Response ◽  
Condition Monitoring ◽  
Spectral Feature ◽  
Response Measurement ◽  
Railway Traffic ◽  
Railway Infrastructure ◽  
Vertical Accelerations ◽  
Condition Indicator ◽  
Inertial Measurements ◽  
Common Crossing

A railway turnout is an element of the railway infrastructure that influences the reliability of a railway traffic operation the most. The growing necessity for the reliability and availability in the railway transportation promotes a wide use of condition monitoring systems. These systems are typically based on the measurement of the dynamic response during operation. The inertial dynamic response measurement with on-board systems is the simplest and reliable way of monitoring the railway infrastructure. However, the new possibilities of condition monitoring are faced with new challenges of the measured information utilization. The paper deals with the condition monitoring of the most critical part of turnouts - the common crossing. The application of an on-board inertial measurement system ESAH-F for a crossing condition monitoring is presented and explained. The inertial measurements are characterized with the low correlation of maximal vertical accelerations to the lifetime. The data mining approach is used to recover the latent relations in the measurement’s information. An additional time domain and spectral feature sets are extracted from axle-box acceleration signals. The popular spectral kurtosis features are used additionally to the wavelet ones. The feature monotonicity ranking is carried out to select the most suited features for the condition indicator. The most significant features are fused in a one condition indicator with a principal component analysis. The proposed condition indicator delivers an almost two-time higher correlation to the lifetime as the maximal vertical accelerations. The regression analysis of the indicator to the lifetime with an exponential fit proves its good applicability for the crossing residual useful life prognosis.

A Precise Time Step Integration Method

1994 ◽  
Vol 208 (6) ◽  
pp. 427-430 ◽  
Author(s):  
W X Zhong ◽  
F W Williams
Keyword(s):  
High Precision ◽  
Integration Method ◽  
Linear Time ◽  
Step Size ◽  
Time Step ◽  
Structural Dynamic ◽  
Time Step Size ◽  
Linear Time Invariant ◽  
Wide Range ◽  
Time Invariant

A high-precision numerical time step integration method is proposed for a linear time-invariant structural dynamic system. Its numerical results are almost identical to the precise solution and are almost independent of the time step size for a wide range of step sizes. Numerical examples illustrate this high precision.

Simulation of Time Histories of Second-Order Wave Effects by Pseudo-Linear Transformation

1995 ◽  
Vol 117 (2) ◽  
pp. 78-84
Author(s):  
Y. Li
Keyword(s):  
Dynamic Response ◽  
Time History ◽  
Second Order ◽  
Hilbert Transforms ◽  
Structural Dynamic ◽  
Quadratic Transformation ◽  
Wave Effects ◽  
Time Histories ◽  
Component Wave ◽  
The Time Domain

Simulation of the time histories of second-order wave effects is often performed by quadratic transformation of a wave time history. By the present approach, the quadratic transformation of waves is approximated by linear combinations of the products of component wave time records and their Hilbert transforms. The computational efficiency is greatly enhanced. The efficient quadratic transformation of a time history is for the time domain solution of structural dynamic response, and can also be used as a post-processor of the frequency domain solution for obtaining statistic parameters of dynamic response.

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