Improvement of Response Spectrum Specifications in Dynamic Testing

1990 ◽  
Vol 112 (4) ◽  
pp. 384-387
Author(s):  
C. W. de Silva ◽  
M. Singh ◽  
J. Zaldonis
Keyword(s):  
Test Object ◽  
Dynamic Testing ◽  
Response Spectrum ◽  
Dynamic Test ◽  
Response Spectra ◽  
The Finite Element Method ◽  
Dynamic Information ◽  
Test Specifications ◽  
Support Motion ◽  
Test Objective

Required response spectra (RRS) are commonly used as dynamic-test specifications in product qualification. RRS specification for a product is normally developed by considering the operating environment of the product. This paper presents a technique to improve the RRS specification for a qualification test by employing available dynamic information on the test object. Specifically, a model of the test object subjected to support-motion inputs is employed. In practice, a model for the test object can be conveniently determined by experimental modal analysis or by the finite element method. The method presented in this paper may be viewed as a way to apportion the energy of test excitations among input locations of a test object in order to optimize a test objective. The underlying theory of the method of modifying a specified RRS is outlined and the computational steps of the method are given. A numerical example is presented to illustrate the use of the method.

A Dynamic-Test Procedure for Improving Seismic Qualification Guidelines

1984 ◽  
Vol 106 (2) ◽  
pp. 143-148
Author(s):  
C. W. deSilva
Keyword(s):  
Test Object ◽  
Dynamic Testing ◽  
Test Procedure ◽  
Dynamic Test ◽  
Standard Test ◽  
Modes Of Failure ◽  
Principal Axes ◽  
Black Box Testing ◽  
Three Degree Of Freedom ◽  
Available Information

Several shortcomings of available standards, regulatory guides, and review plans for seismic qualification testing are identified. A rational test nomenclature is proposed. A standard test is developed by optimizing an appropriate test severity measure function. The standard test is a rectilinear test that is equivalent to the three-degree-of-freedom test with uncorrelated excitations, recommended in IEEE-Std. 344. In terms of eigenvectors of a resulting test matrix, a dynamic interpretation is given for principal axes of a test object. The proposed approach to dynamic testing has two main advantages in comparison to the conventional approach of black-box testing. Firstly, knowledge pertaining to test-object dynamics is directly employed in its development. Secondly available information on possible modes of failure in the overall system can be conveniently incorporated into the formulation.

scholarly journals A Multi-Objective Ground Motion Selection Approach Matching the Acceleration and Displacement Response Spectra

2018 ◽  
Vol 10 (12) ◽  
pp. 4659 ◽  
Author(s):  
Yabin Chen ◽  
Longjun Xu ◽  
Xingji Zhu ◽  
Hao Liu
Keyword(s):  
Ground Motion ◽  
Response Spectrum ◽  
Structural Response ◽  
Response Spectra ◽  
Computationally Efficient ◽  
Ground Motion Selection ◽  
Displacement Response ◽  
Rc Frames ◽  
Selection Approach ◽  
Displacement Response Spectra

For seismic resilience-based design (RBD), a selection of recorded time histories for dynamic structural analysis is usually required. In order to make individual structures and communities regain their target functions as promptly as possible, uncertainty of the structural response estimates is in great need of reduction. The ground motion (GM) selection based on a single target response spectrum, such as acceleration or displacement response spectrum, would bias structural response estimates leading significant uncertainty, even though response spectrum variance is taken into account. In addition, resilience of an individual structure is not governed by its own performance, but depends severely on the performance of other systems in the same community. Thus, evaluation of resilience of a community using records matching target spectrum at whole periods would be reasonable because the fundamental periods of systems in the community may be varied. This paper presents a GM selection approach based on a probabilistic framework to find an optimal set of records to match multiple target spectra, including acceleration and displacement response spectra. Two major steps are included in that framework. Generation of multiple sub-spectra from target displacement response spectrum for selecting sets of GMs was proposed as the first step. Likewise, the process as genetic algorithm (GA), evolvement of individuals previously generated, is the second step, rather than using crossover and mutation techniques. A novel technique improving the match between acceleration response spectra of samples and targets is proposed as the second evolvement step. It is proved computationally efficient for the proposed algorithm by comparing with two developed GM selection algorithms. Finally, the proposed algorithm is applied to select GM records according to seismic codes for analysis of four archetype reinforced concrete (RC) frames aiming to evaluate the influence of GM selection considering two design response spectra on structural responses. The implications of design response spectra especially the displacement response spectrum and GM selection algorithm are summarized.

An analytical model of an I-cored coil located above a conductive material with a hole

2018 ◽  
Vol 82 (2) ◽  
pp. 21001
Author(s):  
Grzegorz Tytko ◽  
Leszek Dziczkowski
Keyword(s):  
Test Object ◽  
Middle Layer ◽  
Axially Symmetric ◽  
The Finite Element Method ◽  
Cylindrical Coordinate ◽  
Air Space ◽  
Through Hole ◽  
Tree Method ◽  
Good Agreement ◽  
Made In

The paper examines the problem of an axially symmetric I-cored coil located above a three-layered plate with a hole in the middle layer. A cylindrical coordinate system was applied, wherein the solution domain was truncated in the radial direction. The employment of the truncated region eigenfunction expansion (TREE) method resulted in deriving the final formulas for the change of the coil impedance with regard to the air space, and also pertaining to the test object without a flaw. Formulas for various configurations of the test object, among others for a surface hole, a subsurface hole and a through hole, have been presented. For the purpose of defectoscopy, the influence of the hole in the plate on the impedance components was investigated. The calculations were made in Matlab for frequencies from 100 Hz to 50 kHz. The obtained results were verified using the finite element method (FEM) in Comsol Multiphysics package. A very good agreement was observed in the case of both the resistance and reactance.

scholarly journals Preliminary results of ground-motion characteristics

2012 ◽  
Vol 55 (4) ◽  
Author(s):  
Francesca Bozzoni ◽  
Carlo Giovanni Lai ◽  
Laura Scandella
Keyword(s):  
Ground Motion ◽  
Site Response ◽  
Response Spectrum ◽  
Field Tests ◽  
Response Spectra ◽  
Ground Acceleration ◽  
Preliminary Results ◽  
Emilia Earthquake ◽  
Particle Orbit ◽  
2012 Emilia Earthquake

The preliminary results are presented herein for the engineering applications of the characteristics of the ground motion induced by the May 20, 2012, Emilia earthquake. Shake maps are computed to provide estimates of the spatial distribution of the induced ground motion. The signals recorded at the Mirandola (MRN) station, the closest to the epicenter, have been processed to obtain acceleration, velocity and displacement response spectra. Ground-motion parameters from the MRN recordings are compared with the corresponding estimates from recent ground-motion prediction equations, and with the spectra prescribed by the current Italian Building Code for different return periods. The records from the MRN station are used to plot the particle orbit (hodogram) described by the waveform. The availability of results from geotechnical field tests that were performed at a few sites in the Municipality of Mirandola prior to this earthquake of May 2012 has allowed preliminary assessment of the ground response. The amplification effects at Mirandola are estimated using fully stochastic site-response analyses. The seismic input comprises seven actual records that are compatible with the Italian code-based spectrum that refers to a 475-year return period. The computed acceleration response spectrum and the associated dispersion are compared to the spectra calculated from the recordings of the MRN station. Good agreement is obtained for periods up to 1 s, especially for the peak ground acceleration. For the other periods, the spectral acceleration of the MRN recordings exceeds that of the computed spectra.<br />

Reinforcement Calculated Method Based on Disease Model of DongFu Bridge

2012 ◽  
Vol 178-181 ◽  
pp. 2199-2203
Author(s):  
Peng Jun Liu
Keyword(s):  
Finite Element Method ◽  
Dynamic Testing ◽  
Disease Model ◽  
Reference Value ◽  
Original Structure ◽  
Structure Model ◽  
The Finite Element Method ◽  
Stiffness Reduction ◽  
Shear Area ◽  
Main Bridge

On the basis of the static and dynamic testing of the bridge, the original structure model and the model based on stiffness reduction of Dongfu Bridge were analyzed and calculated with the finite element method. The main problem that the anti-shear area of the section in the middle pivot position is not enough is found. On the basis of combination of the passive and active reinforcement styles, a reasonable and feasible reinforcement plan on the girder beam of the main bridge is raised. These conclusions have an important reference value on the bridge reinforcement.

Comparative Study on the Pseudo-Dynamic Testing of Semi-Rigid Connection of Steel Frames with or without Brace

2011 ◽  
Vol 194-196 ◽  
pp. 2001-2007
Author(s):  
Jia Lv ◽  
Qi Lin Zhang
Keyword(s):  
Dynamic Testing ◽  
Dynamic Test ◽  
Lateral Force ◽  
Steel Frame ◽  
Seismic Loads ◽  
Test Results ◽  
Shearing Force ◽  
Braced Frame ◽  
Rigid Connection ◽  
Steel Braced Frame

The horizontal stiffness of steel frame is relatively weak. So designers introduce brace system into steel frame to increase the horizontal stiffness. In order to guarantee the safety of the structure, we should imitate the performance of the structure under seismic loads. In this paper, the pseudo-dynamic test was conducted on the semi-rigid connection of steel frame and the semi-rigid connection of steel-braced frame. The test results show that the brace can increase the ductility of the structure, decrease the displacement of the top floor, decrease the interlayer displacement, and bear ground floor shearing-force. So the brace greatly impacts the performance of the structure. It has the ability of anti-earthquake and strong resistance ability of lateral force.

Behavior of CFST-RC Pier under Different Ground Motions

2018 ◽  
Vol 1145 ◽  
pp. 134-139
Author(s):  
Raghabendra Yadav ◽  
Bao Chun Chen ◽  
Hui Hui Yuan ◽  
Zhi Bin Lian
Keyword(s):  
Earthquake Engineering ◽  
Large Scale ◽  
Dynamic Testing ◽  
Ground Motions ◽  
Dynamic Test ◽  
Longitudinal Direction ◽  
Steel Tube ◽  
Engineering Research ◽  
Magnification Factors ◽  
Time Histories

The dynamic testing of large-scale structures continues to play a significant role in earthquake engineering research. The pseudo- dynamic test (PDT) is an experimental technique for simulating the earthquake response of structures and structural components in time domain. A CFST-RC pier is a modified form of CFST laced column in which CFST members are connected with RC web in longitudinal direction and with steel tube in transverse direction. For this study, a CFST -RC pier is tested under three different earthquake time histories having scaled PGA of 0.05g. From the experiment acceleration, velocity, displacement and load time histories are observed. The dynamic magnification factors for acceleration due to Chamoli, Gorkha and Wenchuan ground motions are observed as 12, 10 and 10 respectively. The frequency of the pier is found to be 1.42 Hz. The result shows that this type of pier has excellent static and earthquake resistant properties.

Characteristic of Fuzzy, ANN, and ANFIS for Brushless DC Motor Controller: An Evaluation by Dynamic Test

2021 ◽  
Vol 13 (6) ◽  
Author(s):  
◽  
Andi Setiawan ◽  
Bayu Rudiyanto ◽  
Satryo Budi Utomo ◽  
Muji Muji Setiyo ◽  
...  
Keyword(s):  
Fuzzy Logic Controller ◽  
Fuzzy Inference ◽  
Dynamic Testing ◽  
Dynamic Test ◽  
Absolute Error ◽  
Inference System ◽  
Brushless Dc ◽  
Average Value ◽  
Constant Torque ◽  
Artificial Neural Network Ann

Brushless DC (BLDC) motors are the most popular motors used by the industry because they are easy to control. BLDC motors are generally controlled by artificial controls such as Fuzzy Logic Controller (FLC), Artificial Neural Network (ANN), and Adaptive Neuro-Fuzzy Inference System (ANFIS). However, the performance of the BLDC control system in previous studies was compared separately with their respective parameters, making it difficult to evaluate comprehensively. Therefore, in order to investigate the characteristic performance of Fuzzy, ANN, and ANFIS, this article provides a comparison of these artificial controls. Two scenarios of the dynamic tests are conducted to investigate control performance under constant torque-various speed and constant speed-various torque. By dynamic testing, characteristics of Fuzzy, ANN, and ANFIS can be observed as real applications. The testing parameters are: Settling Time, Overshoot and Overdamp (in the graph and average value), and then statistic performance are: Integral Square Error (ISE), Integral Absolute Error (IAE), Integral Time Absolute Error (ITAE), and Mean Absolute Error (MAE). The test result in scenario 1 showed that the ANN has a better performance compared to other controllers with the MAE, IAE, ITAE, and ISE value of 31.3003; 105.6280; 208.0630; and 5,7289 e4, respectively. However, in scenario 2, ANN only has a better performance compared to other controllers on just a few parameters. In scenario 2, ANN is indeed able to maintain speed but it has a more ripple value than ANFIS. Even so, the ripple that occurs in ANN does not have too much value compared to the setpoint. Therefore, the MAE value of the ANN is smaller than the ANFIS (18.8937 of ANN and 28.4685 of ANFIS).

Response spectral matching of horizontal ground motion components to an orientation-independent spectrum (RotDnn)

2020 ◽  
pp. 875529302097098
Author(s):  
Luis A Montejo
Keyword(s):  
Ground Motion ◽  
Response Spectrum ◽  
Time History ◽  
Response Spectra ◽  
Major Axis ◽  
Component Level ◽  
Nonlinear Characteristics ◽  
Target Spectrum ◽  
Horizontal Ground Motion ◽  
Median Spectrum

This article presents a methodology to spectrally match two horizontal ground motion components to an orientation-independent target spectrum (RotDnn). The algorithm is based on the continuous wavelet transform decomposition and iterative manipulation of the two horizontal components of a seed record. The numerical examples presented follow current ASCE/SEI 7 specifications and therefore maximum-direction spectra (RotD100) are used as target for the match. However, the proposed methodology can be used to match other RotDnn spectra, like the median spectrum (RotD50). It is shown that with the proposed methodology the resulting RotDnn from the modified horizontal components closely match the smooth target RotDnn spectrum, while the response spectrum for each horizontal component continue to exhibit a realistic jagged behavior. The response spectra variability at the component level within suites of spectrally matched motions was found to be of the same order than the variability measured in suites composed of amplitude scaled records. Moreover, the spectrally matched records generated preserved most of the characteristics of the seed records, including the nonlinear characteristics of the time history traces and the period-dependent major axis orientations.

Compatibility of Palm Biodiesel Blends on the Existing Elastomer Fuel Hose in Diesel Engine with Approach of Dynamic Test Rig: A Concept Study

2020 ◽  
Vol 1010 ◽  
pp. 172-177
Author(s):  
Narisa Sa'at ◽  
Ariffin Samsuri ◽  
Noradila Abdul Latif ◽  
Nurul Fitriah Nasir ◽  
Rais Hanizam Madon ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Alternative Fuels ◽  
Dynamic Testing ◽  
Dynamic Test ◽  
Field Trials ◽  
Biodiesel Fuel ◽  
Compatibility Study ◽  
Fuel System ◽  
Experimental Conditions

Elastomer is one of the important material for the hoses, sealants and tubes in the components of fuel delivery system in diesel engine vehicles due to the factor of compatibility with diesel fuel. However, concern were arise that presence of alcohol, fatty acid component and other factors such as water content in the alternative fuels which is blended biodiesel fuel and different chemical composition from the diesel fuel may increase further uncertainty to the consumer of diesel engine or diesel engine manufacturers in terms of compatibility issue. Thus this paper intends to assess current and typical test standards on their efficacy of representing the fuel system of diesel engine vehicles. Respectively, ASTM D471 are based on laboratory immersion studies and the experimental conditions are differ from the real service conditions in the fuel system of diesel engine vehicles. Even though number of previous studies regarding to the compatibility of elastomer components has been reported, there is a need to set up the exact material that present in the fuel system of diesel engine vehicles. This is especially right for elastomers since their resistance is mainly depends on their elemental compositions. As such, introduction of the dynamic testing approach that may be applied when assessing the compatibility study between blended biodiesel fuel that simulate the actual fuel system of a diesel engine vehicles before carrying out in the field trials.

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