scholarly journals Calculating static deformations from quick-release accelerograms

1990 ◽  
Vol 23 (4) ◽  
pp. 239-253
Author(s):  
Bruce M. Douglas ◽  
Emmanuel A. Maragakis ◽  
Bhabananda Nath
Keyword(s):  
Dynamic Testing ◽  
Highway Bridges ◽  
Correction Method ◽  
Step Function ◽  
Base Line ◽  
Quick Release ◽  
Testing Method ◽  
Scale Test ◽  
Measured Displacement ◽  
Dynamic Excitations

This paper outlines a new method for performing base line corrections on accelerograms generated by the quick-release dynamic testing method. These accelerograms are produced when highway bridges are subjected to dynamic excitations by initially deforming the bridge structure and subsequently quick-releasing the loads causing the deformation. This base line correction method is developed in such a way that the step function character of the quick-release base line is preserved. It is this feature which allows the static deformations of the structure to be recovered by integrating the accelerograms. The reliability of the method is demonstrated by a series of laboratory measurements comparing the displacement time series obtained by double integration to independently measured displacement responses. These laboratory comparisons indicate that the offset displacements are accurate to within about 5% on the average. The method was applied on accelerograms obtained during a quick-release full-scale test of the Meloland Road Overcrossing, and some examples of this application are presented.

Static and dynamic testing of highway bridges: a best practice example

2019 ◽  
Vol 10 (1) ◽  
pp. 43-56 ◽  
Author(s):  
Marcheggiani Laura ◽  
Clementi Francesco ◽  
Formisano Antonio
Keyword(s):  
Best Practice ◽  
Dynamic Testing ◽  
Highway Bridges

Numerical and Experimental Assessment of the Highway Arch Viaduct

2015 ◽  
Vol 769 ◽  
pp. 252-259
Author(s):  
Jan Bencat ◽  
Maria Stehlikova ◽  
Milan Skarupa
Keyword(s):  
Dynamic Testing ◽  
Highway Bridges ◽  
Structural Condition ◽  
Traffic Load ◽  
Analytical Models ◽  
Mode Shapes ◽  
Bridge Structure ◽  
Modal Damping ◽  
Bridge Structures ◽  
And Performance

Full–scale dynamic testing of bridge structures can provide valuable information on the service behavior and performance of structures. With the growing interest in the structural condition of highway bridges, dynamic testing can be used as a tool for assessing the integrity of bridges. From the measured dynamic response, induced by instructed passing trucks, modal parameters (natural frequencies, mode shapes and modal damping values) and system parameters (stiffness, mass and damping matrices) are obtained. These identified parameters can then be used to characterize and monitor the service of the bridge structure in the future. Analytical models of the structure can also be validated using these parameters [1,2]. The paper presents a procedure for estimating the traffic load bearing capacity of the steel arch highway viaduct Bridge Structure 205 (DC1–9, 755 m) constructed on Highway D1 in Nord Slovakia (Fig. 1) over the natural hollow basin via dynamic tests of the viaduct structures.

The Dynamic Testing Method for Damage Diagnosis of Multi-Story Masonry Buildings

2011 ◽  
Vol 368-373 ◽  
pp. 1148-1151
Author(s):  
Feng Ge Li ◽  
Hong Yu
Keyword(s):  
Neural Network ◽  
Numerical Computation ◽  
Bp Neural Network ◽  
Dynamic Testing ◽  
Masonry Structure ◽  
Masonry Buildings ◽  
Damage Diagnosis ◽  
Testing Method ◽  
Damage Indicator ◽  
Artificial Network

A new method to diagnose the damage of masonry structure using artificial network is brought forward. The frequencies and the ratio of change for any two orders various frequencies is chosen as a damage indicator and is used to train the BP neural network, which can diagnose the damage of masonry structure. The result of the numerical computation shows that the BP neural network can diagnose the damage of masonry structure.

Passenger Air Bag Linear Impactor Dynamic Testing Method and Data Analysis

2007 ◽  
Author(s):  
Stephen H. Kang ◽  
Ellen Barnes ◽  
Sing Liu ◽  
Matt Lenart ◽  
Matt Maher
Keyword(s):  
Data Analysis ◽  
Dynamic Testing ◽  
Testing Method ◽  
Air Bag

A new dynamic testing method for elastic, shear modulus and Poisson’s ratio of concrete

2015 ◽  
Vol 100 ◽  
pp. 129-135 ◽  
Author(s):  
Zhiheng Wang ◽  
Zizhen Gao ◽  
Yunlu Wang ◽  
Yu Cao ◽  
Ganggang Wang ◽  
...  
Keyword(s):  
Shear Modulus ◽  
Poisson’S Ratio ◽  
Dynamic Testing ◽  
Poisson's Ratio ◽  
Testing Method ◽  
Elastic Shear Modulus ◽  
Elastic Shear

scholarly journals Delay Testing Method for Off-Site Asynchronous LTE Networks Based on Singular Value Removal

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Shuangshuang Ni ◽  
Ke Cui ◽  
Kai Zhang ◽  
Guoxin Zheng
Keyword(s):  
Singular Values ◽  
Correction Method ◽  
Transmission Delay ◽  
Delay Test ◽  
Lte Networks ◽  
Train Control ◽  
Testing Method ◽  
Before And After ◽  
Clock Correction

This paper presents an experimental campaign of transmission delay measurements under asynchronous condition for the communication-based train control (CBTC) systems. A three-stage asynchronous clock correction method is proposed. Before and after the working stage, the clock difference between transmitter and the receiver is calculated, moreover the relative offset and relative skew between two terminals of the working stage are derived, and it further leads towards the experimental verification of the transmission delay. In order to improve the measurement accuracy, the singular values are distinguished and eliminated in the test. Using this method, the transmission delay of the Long-Term Evolution for Metro (LTE-M) communication between the train and the signalling room in Shanghai Zhangjiang Metro Training Line is measured successfully, which demonstrates the effectiveness of the proposed one-way transmission delay test.

scholarly journals STUDY OF NUTRITIONAL CONSTITUENTS AND SENSORY EVALUATION OF BAKERY PRODUCTS PREPARED FROM SEED AND BARK OF PRUNUS PERSICA (PEACH)

2016 ◽  
Vol 4 (6) ◽  
pp. 12-24
Author(s):  
Neha Qumar
Keyword(s):  
Prunus Persica ◽  
Rating Scale ◽  
Proximate Analysis ◽  
Base Line ◽  
Inflammatory Agent ◽  
Trained Panel ◽  
Significant Difference ◽  
Scale Test ◽  
Pharmaceutical Industries ◽  
Nutritional Constituents

Medicinal plants are local heritage with global importance. Prunuspersica Seeds and Bark are used as traditional medicine for treatment of blood diseases, anemia rheumatism jaundice, antioxidant and anti-inflammatory agent. So the present study was planned for analysed the nutritional constituents of Prunuspersica Seeds and Bark such as Moisture, Protein, fat and ash were analyzed using AOAC methods. Carbohydrate content of the sample was estimated by Difference method. The research was designed to investigate proximate composition. The results of proximate analysis indicated that seeds and bark had appreciable amounts of Protein (2.2% and 1.0%), Carbohydrate (50.3% and 58.7%) and fat (36.9% and 29.2%) on dry basis with observed no significant difference (P≤0.05). Acceptability evaluation of prepared recopies was performed by semi trained panel through 9 point Hedonic rating scale test. The result revealed that among the recipes (Biscuits and Baked bite) prepared by adding 2%, 4%, 6% and 8% Powder of Seed and Bark that variant 1, 2 and 3 were acceptable when comparable to standard recipe. There is no significance difference (P≤0.005) when they were tested statistically. Considering the pharmaceutical action of Seeds and Bark for treatment of many diseases and that the reasonably safe to use, its development is important for the pharmaceutical industries. This study generated base line information about the peach Seeds and Bark which will be beneficial to treat various diseases. This study also indicates that both Seeds and Bark can be valuable in generating awareness among people to control various diseases and to improve their nutrition and health status.

scholarly journals Parameter identification of soil-pile system by the dynamic testing method

1997 ◽  
Vol 19 (3) ◽  
pp. 45-51
Author(s):  
Nguyen Tien Khiem
Keyword(s):  
Natural Frequencies ◽  
Dynamic Testing ◽  
Spectral Characteristics ◽  
Numerical Test ◽  
High Accuracy ◽  
Modal Parameters ◽  
Unknown Parameters ◽  
Testing Method ◽  
Pile Length ◽  
Elastic Coefficients

This paper deals with a problem to determinate parameters of soil and pile by measurements of natural frequencies and damping ratios of the system. There was suggested a model of soil-pile system, which includes more unknown parameters of soil to be determined. Here is given also mathematical base for extraction of modal parameters from measured spectral characteristics. The most important result obtained in this study is a procedure and' program carried out to determinate the pile length (L), elastic coefficients of soil around pile and at the bottom end of pile and also the damping coefficient of soil. Numerical test by the program shows high accuracy and validates effectiveness of the procedure.

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