Development of a Versatile Hybrid Testing System for Seismic Experimentation

2012 ◽  
Vol 38 (6) ◽  
pp. 44-60 ◽  
Author(s):  
X. Shao ◽  
G. Enyart
Keyword(s):  
Testing System ◽  
Hybrid Testing

Performance Specifications for Real-Time Hybrid Testing of 1:50-Scale Floating Wind Turbine Models

2014 ◽  
Author(s):  
Matthew Hall ◽  
Javier Moreno ◽  
Krish Thiagarajan
Keyword(s):  
Wind Turbine ◽  
Real Time ◽  
Sensitivity Study ◽  
Scale Model ◽  
Testing System ◽  
Floating Platform ◽  
Hybrid Testing ◽  
Actuation Mechanism ◽  
Floating Wind Turbine ◽  
Performance Specifications

This paper presents performance requirements for a real-time hybrid testing system to be suitable for scale-model floating wind turbine experiments. In the wave basin, real-time hybrid testing could be used to replace the model wind turbine with an actuation mechanism, driven by a wind turbine simulation running in parallel with, and reacting to, the experiment. The actuation mechanism, attached to the floating platform, would provide the full range of forces normally provided by the model wind turbine. This arrangement could resolve scaling incompatibilities that currently challenge scale-model floating wind turbine experiments. In this paper, published experimental results and a collection of full-scale simulations are used to determine what performance specifications such a system would need to meet. First, an analysis of full-scale numerical simulations and published 1:50-scale experimental results is presented. This analysis indicates the required operating envelope of the actuation system in terms of displacements, velocities, accelerations, and forces. Next, a sensitivity study using a customization of the floating wind turbine simulator FAST is described. Errors in the coupling between the wind turbine and the floating platform are used to represent the various inaccuracies and delays that could be introduced by a real-time hybrid testing system. Results of this sensitivity study indicate the requirements — in terms of motion-tracking accuracy, force actuation accuracy, and system latency — for maintaining an acceptable level of accuracy in 1:50-scale floating wind turbine experiments using real-time hybrid testing.

Experimental investigation of a compound force tracking control strategy for electro-hydraulic hybrid testing system with suppression of vibration disturbances

2016 ◽  
Vol 231 (6) ◽  
pp. 1033-1056 ◽  
Author(s):  
Zhencai Zhu ◽  
Yu Tang ◽  
Gang Shen
Keyword(s):  
Control Strategy ◽  
Tracking Control ◽  
Disturbance Observer ◽  
Inverse Model ◽  
Testing System ◽  
Control Voltage ◽  
Hybrid Testing ◽  
Seismic Engineering ◽  
Hydraulic Hybrid ◽  
Force Tracking

Electro-hydraulic hybrid testing, which imposes the desired acceleration and force on the specimen in parallel, is a novel structural testing method for structures or facilities and is extensively applied in civil and seismic engineering. To efficiently suppress the surplus force resulted from the acceleration motion of the specimen during the force control process, a compound force tracking control strategy comprised of a force and voltage feedforward controller (FVFC) and feedforward inverse with disturbance observer (FIDOB) controller is presented in this research. The FVFC controller as an inner loop feedforward component is first constituted by the generated force feedback signal and the real-time control voltage signal of the acceleration actuator so as to compensate for the acceleration motion of the specimen for a better disturbance rejection performance, and the FVFC controller requires little information of the system dynamic structure or parameters. The FIDOB controller composed by a feedforward inverse controller and an inverse model-based disturbance observer is then combined with the FVFC controller as an outer loop to further deal with the remaining disturbances for the FVFC-controlled electro-hydraulic hybrid testing system. The inverse model applied in the FIDOB controller is obtained with the frequency domain complex curve fitting and zero magnitude error tracking technology with respect to the proportional–integral controlled static loading system. Hence, the proposed controller integrates the advantages of the FVFC controller and FIDOB controller in terms of easy implementation and high tracking performance. Finally, comparative experiments are carried out on an uniaxial electro-hydraulic hybrid testing test rig with the xPC rapid prototyping technology and experimental results demonstrate the effectiveness of the proposed control strategy.

Hybrid testing with model updating on steel panel damper substructures using a multi‐axial testing system

2018 ◽  
Vol 48 (3) ◽  
pp. 347-365
Author(s):  
Kung‐Juin Wang ◽  
Ming‐Chieh Chuang ◽  
Keh‐Chyuan Tsai ◽  
Chao‐Hsien Li ◽  
Pu‐Yuan Chin ◽  
...  
Keyword(s):  
Model Updating ◽  
Testing System ◽  
Hybrid Testing ◽  
Steel Panel

Comparison of Examinees’ and Doctors’ Judgement of Health Status Using Data in an AMHTS

1984 ◽  
Vol 23 (01) ◽  
pp. 15-22
Author(s):  
Y. Sekita ◽  
T. Ohta ◽  
M. Inoue ◽  
H. Takeda
Keyword(s):  
Health Status ◽  
Discriminant Analysis ◽  
Explanatory Power ◽  
Laboratory Data ◽  
Subjective Symptom ◽  
Health Conditions ◽  
Testing System ◽  
Multiple Discriminant Analysis ◽  
Canonical Axis ◽  
Using Data

SummaryJudgements of examinees’ health status by doctors and by the examinees themselves are compared applying multiple discriminant analysis. The doctors’ judgements of the examinees’ health status are studied comparatively using laboratory data and the examinees’ subjective symptom data.This data was obtained in an Automated Multiphasic Health Testing System. We discuss the health conditions which are significant for the judgement of doctors about the examinees. The results show that the explanatory power, when using subjective symptom data, is fair in the case of the doctors’ judgement. We found common variables, such as nervousness, lack of perseverance etc., which form the first canonical axis.

Fatigue of Unidirectional Cord-Rubber Composites

1999 ◽  
Vol 27 (1) ◽  
pp. 48-57 ◽  
Author(s):  
Y. Liu ◽  
Z. Wan ◽  
Z. Tian ◽  
X. Du ◽  
J. Jiang ◽  
...  
Keyword(s):  
Damage Accumulation ◽  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Constant Load ◽  
Testing System ◽  
Rubber Composites ◽  
Cycle Frequency ◽  
Periodic Loading ◽  
Fatigue Damage Accumulation ◽  
Rubber Composite

Abstract A fatigue testing system is established with which the real-time recording of stress, strain, temperature, and hysteresis loss of rubbers or cord-rubber composite specimens subjected to periodic loading or extension can be successfully carried out. Several problems are connected with the experimental study of the fatigue of rubber composites. In constant extension cycling, the specimen becomes relaxed because of the viscoelasticity of rubber composites, and the imposed tension-tension deformation becomes complex. In this method, the specimen is unlikely to fail unless the imposed extensions are very large. Constant load cycling can avoid the shortcomings of constant extension cycling. The specially designed clamps ensure that the specimen does not slip when the load retains a constant value. The Deformation and fatigue damage accumulation processes of rubber composites under periodic loading are also examined. Obviously, the effect of cycle frequency on the fatigue life of rubber composites can not be ignored because of the viscoelasticity of constituent materials. The increase of specimen surface temperature is relatively small in the case of 1 Hz, but the temperature can easily reach 100°C at the 8 Hz frequency. A method for evaluating the fatigue behavior of tires is proposed.

IELTS READING AND SOME TECHNIQUES TO IMPROVE IELTS READING SKILLS FOR STUDENTS

2019 ◽  
Vol 8 (2) ◽  
Author(s):  
Dinh Thi Bac Binh ◽  
Dinh Thi Kieu Trinh
Keyword(s):  
English Language ◽  
Reading Skills ◽  
Language Testing ◽  
Training Institution ◽  
Testing System ◽  
Time Saving ◽  
International English

The International English Language Testing System (IELTS) is recognized as an accountable tool to assess whether aperson is able to study or train in English. Every year, thousandsof students sit for IELTS. However, the number of those who arerecognized to be capable enough to take a course in English issomehow limited, especially for those who are not major inEnglish at their universities.IELTS Reading is considered as a discerning skill and it is of theequal importance to listening, speaking and writing in obtainingthe objectives of IELTS of band 6 or 6.5. Being teachers of Englishat a training institution, the authors recognize that students canmake time-saving improvements in their reading command undertheir teachers’ insightful guidance.

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