The Similar Relationship Research of the L-Type Eccentric Structure Model on Vibration Test

2015 ◽  
Vol 724 ◽  
pp. 256-260
Author(s):  
Ai Jun Chen ◽  
Xiao Mei Jiang ◽  
Guo Jing He
Keyword(s):  
Model Test ◽  
Similarity Theory ◽  
Frame Structure ◽  
Seismic Action ◽  
Test Model ◽  
Structure Model ◽  
Correct Formula ◽  
Important Means ◽  
Eccentric Structure ◽  
Scaled Models

Vibroplatform test is an important means of testing the dynamic characteristics of the laboratory sim-ulating structure under seismic action. For structure whose volume and weight exceed the limits of vibroplatfor-m tests is usually carried out through model test according to the similarity theory. So how to deal with the simil-ar relationships among the test model and how to verify thethe rationality of vibration control strategy through testing results become the key and fundamentalproblems. 1:15 scaled models will be made through the dimensional analysis based on a 4 layersL-shaped frame structure as the proto-type , which are made from micro-concrete, aluminum alloyand plexiglass. SFMT sap2000 is used to make a dynamic analysis to get the values of period,acceleration, velocity, etc. Comparing the results of prototype inferred from model through similarrelationship with theoretica-l values of prototype to get the correct formula and confirm the bestscaled model and then provide references f-or model test later.

Experimental and Simulation Study of a Hybrid Frame Structure with Viscous Dampers

2012 ◽  
Vol 446-449 ◽  
pp. 894-899
Author(s):  
Hong Mei Zhang ◽  
Xi Lin Lu ◽  
Chun Guang Meng
Keyword(s):  
Shaking Table Test ◽  
Time History ◽  
Shaking Table ◽  
Frame Structure ◽  
Nonlinear Time History Analysis ◽  
Seismic Action ◽  
Test Model ◽  
Viscous Dampers ◽  
Scaled Model ◽  
Nonlinear Simulation

A Concrete-filled Rectangular Steel Tube (CRST) frame structure is studied in this paper by shaking table model test and nonlinear simulation. A number of viscous dampers are employed to insure the function of the building especially under seismic action for some of the main vertical elements of the building are not continuous. A shaking table test of a scaled model was conducted under different earthquake waves to investigate the structural behavior. And the nonlinear time-history analysis for the shaking table test model was also carried out by finite element analysis program according to the shaking table test. The simulation model was constructed in accordance with the tested specimen and the simulation effect was then validated by the tested results. To sum up, (1) there are no obvious weak stories on the damping equipped structure; (2) the dampers can reduce the displacement of the irregular to a certain degree.

The Numerical Analysis of Isolation System in the Sandwich Structure Based on Properties of Reinforced Concrete

2013 ◽  
Vol 788 ◽  
pp. 578-581
Author(s):  
Ying Rong Wei ◽  
Fu Ma
Keyword(s):  
Numerical Analysis ◽  
Layer Structure ◽  
Response Spectrum ◽  
Steel Frame ◽  
Frame Structure ◽  
Seismic Action ◽  
Structure Model ◽  
Element Analysis ◽  
Concrete Frame ◽  
Steel Frame Structure

The calculation of isolated structures mature finite element analysis software MIDAS / Gen choice of 8 degrees Area with five framework for the establishment of the original five-layer structure model, the five-story concrete frame + two layers of steel frame structure model, the five-story concrete frame + two layers of concrete frame structure model, the five-story concrete frame + two layers of steel frame structure model (isolation), the five-story concrete frame two layers of concrete frame structure model (isolated) five models numerical Analysis. Being frequently occurred earthquake response spectrum analysis to come to the results that the building structure using additional layers isolation measures compare with not using layer structure measures, the former can significantly reduce the seismic action [1].

Structural similitudes of stiffened cylinders

2017 ◽  
Vol 24 (3) ◽  
pp. 527-541 ◽  
Author(s):  
G Petrone ◽  
M Manfredonia ◽  
S De Rosa ◽  
F Franco
Keyword(s):  
Numerical Simulation ◽  
Structural Engineering ◽  
Scaling Laws ◽  
Similarity Theory ◽  
Design Tool ◽  
Engineering Science ◽  
The Finite Element Method ◽  
Engineering Problems ◽  
Incomplete Similarity ◽  
Scaled Models

Similarity theory is a branch of engineering science that deals with establishing conditions of similarity among phenomena and is applied to various fields, such as structural engineering problems, vibration and impact. Tests and numerical simulation of scaled models are still a valuable design tool, whose purpose is to accurately predict the behaviour of large or small prototypes through scaling laws applied to the experimental and numerical results. The aim of this paper is to predict the behaviour of the complete and incomplete similarity of stiffened cylinders by applying distorted scaling laws of the models in similitude. The investigation is performed using models based on the finite element method within commercial software. Two classes of cylinders scaled, with different laws, and, hence, reproducing replicas (exact similitude) and avatars (distorted similitude) are investigated.

Dynamic Response of Frame Structure with Different Stiffness in Two Horizontal Directions under Oblique Seismic Action

2013 ◽  
Vol 368-370 ◽  
pp. 1644-1647
Author(s):  
Zhen Bao Li ◽  
Hai Teng Wang ◽  
Li Fei Liu ◽  
Wen Jing Wang
Keyword(s):  
Dynamic Response ◽  
Ground Motion ◽  
Structure Design ◽  
Frame Structure ◽  
Maximum Response ◽  
Seismic Action

The ground motion is multidimensional, random and uncertain in directions when earthquakes occur, so dynamic response under oblique seismic action needs to be considered in the structure design. A frame structure with different stiffness in two horizontal directions was analyzed under seismic action with different input angles. The maximum response of beams and columns was obtained. The seismic mechanism of structures under oblique seismic action was discussed.

Experimental Study on Non-Perpendicular Frame Structure of Tall Building

2008 ◽  
Vol 400-402 ◽  
pp. 593-598
Author(s):  
Wei Xing Shi ◽  
Cheng Qing Liu ◽  
Xi Lin Lu ◽  
Song Zhang ◽  
Ying Zhou
Keyword(s):  
Similarity Theory ◽  
Structural Type ◽  
Shaking Table ◽  
Frame Structure ◽  
Scale Model ◽  
Prototype Structure ◽  
Table Model ◽  
Practical Engineering ◽  
Whiplash Effect ◽  
Shaking Table Model Test

A shaking table model test is conducted for Guangzhou West Tower to study its seismic behavior in State Key Laboratory for Disaster Reduction in Civil Engineering at Tongji University. Guangzhou West Tower adopts a new structure system and the significant characteristic of this system is the non-perpendicular frame arranged around the building, acting both as columns and bracings. Based on the similarity theory and member equivalent principle，a 1/80 scale model of this building is made of polymethyl methacrylate(PMMA). The model’s dynamic characteristics, earthquake-resistant behavior, responses of acceleration and deformation under different wave peak values are investigated, then the seismic responses of the prototype structure are deduced and analyzed. The whiplash effect of the prototype structure is studied, and the weak position of the structure is found out. The experiment results demonstrate that it is feasible to apply this structural type to practical engineering. Finally, some suggestions for the engineering design of the prototype structure are put forward.

Model Test Techniques Developed to Investigate the Wind Heeling Characteristics of Sailing Vessels and Their Response to Gusts

1991 ◽  
Author(s):  
Barry Deakin
Keyword(s):  
Wind Tunnel ◽  
Model Test ◽  
Wind Tunnels ◽  
Stability Assessment ◽  
Tunnel Floor ◽  
The Stability ◽  
Scaled Models ◽  
Scale Data ◽  
Heeling Moment ◽  
Gust Response

During the development of new stability regulations for the U.K. Department of Transport, doubt was cast over many of the assumptions made when assessing the stability of sailing vessels. In order to investigate the traditional methods a programme of work was undertaken including wind tunnel tests and full scale data acquisition. The work resulted in a much improved understanding of the behaviour of sailing vessels and indeed indicated that the conventional methods of stability assessment are invalid, the rules now applied in the U.K. being very different to those in use elsewhere. The paper concentrates on the model test techniques which were developed specifically for this project but which will have implications to other vessel types. The tests were of two kinds: measurement of the wind forces and moments on a sailing vessel; and investigation of the response of sailing vessels to gusts of wind. For the force and moment measurements models were mounted in a tank of water on a six component balance and tested in a large boundary layer wind tunnel. Previous tests in wind tunnels have always concentrated on performance and the heeling moments have not normally been measured correctly. As the measurements of heeling moment at a range of heel angles was of prime importance a new balance and mounting system was developed which enabled the above water part of the vessel to be modelled correctly, the underwater part to be unaffected by the wind, and the interface to be correctly represented without interference. Various effects were investigated including rig type, sheeting, heading, heel angle and wind gradient. The gust response tests were conducted with Froude scaled models floating in a pond set in the wind tunnel floor. A mechanism was installed in the tunnel which enabled gusts of various characteristics to be generated, and the roll response of the models was measured with a gyroscope. These tests provided information on the effects of inertia, damping, rolling and the characteristics of the gust. Sample results are presented to illustrate the uses to which these techniques have been put.

scholarly journals Structural Seismic Damage Assessment Method Based on Structural Dynamic Characteristics

2022 ◽  
Author(s):  
Mingzhen Wang ◽  
Lin Gao ◽  
Zailin Yang
Keyword(s):  
Damage Assessment ◽  
Seismic Damage ◽  
Assessment Method ◽  
Frame Structure ◽  
Fundamental Period ◽  
Deformation Pattern ◽  
Seismic Action ◽  
Building Structure ◽  
Structural Dynamic ◽  
Seismic Damage Assessment

Abstract The seismic damage state of building structure can be evaluated by observing the fundamental period change of structure. Firstly, the fundamental period calculation formula that adapts to the deformation pattern and distribution mode of horizontal seismic action for reinforced concrete frame structure is derived. Secondly, the seismic damage assessment standard of building structure considering period variation is established. Then, the seismic damage assessment method of building structure is constructed. Finally, the seismic damage example is used to verify the established evaluation method. The results show that the established research method has high accuracy and good engineering practicability.

scholarly journals Radial Joints Behavior of a Precast Asymmetric Underpass Induced by Long-Term Loads of Ground Vehicles

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Zhiyi Jin ◽  
Taiyue Qi ◽  
Xiao Liang ◽  
Bo Lei ◽  
Yangyang Yu ◽  
...  
Keyword(s):  
Transient Response ◽  
Model Test ◽  
Similarity Theory ◽  
Rapid Development ◽  
Design Stage ◽  
Physical Model Test ◽  
Scaled Model ◽  
Joint Opening ◽  
Assembly Technology

With the rapid development of the urbanization, many underpasses are designed and constructed in big cities to alleviate the huge traffic pressure. The construction method has been changed from traditional on-site concrete pouring technology to prefabricated assembly technology. However, this change will inevitably bring out some new problems to be studied such as the behaviour of the radial joints. In this study, the numerical simulation model of Moziqiao precast and assemble underpass with large asymmetric cross section was constructed by using the ABAQUS software to study the transient response of the underpass induced by ground surface dynamic load. Based on the similarity theory a 1/10 scaled model test was carried out to study the long-term radial joint behaviour of the underpass considering the prestress loss during the 2000 000 loading cycles. The results transient dynamic response from computed and tested was compared in terms of acceleration. The comparison showed that the transient response accelerations have good consistency. The results of the physical model test were analysed in terms of joint opening, closure, and slipping. The accumulative joint opening was closely correlated to the prestress level, and the joint opening at different prestress levels increased with the loss of the prestress. The joints closure decreased with the increase of the previous accumulative color value. The joint slipping mainly attributed to the slipping of the top segment. Both the opening and slipping of the joints at RJ 1 were larger than that of RJ3 due to the wider span of RJ1, which reflected an asymmetric effect. This study revealed the long-term accumulative behaviour of the radial joints, which convinced us that the long-term accumulative deformation of the joints should be taken into consideration during the design stage for similar projects.

Numerical Simulation Research on Aerodynamic Characteristics of the Fixed Transition Airfoil

2013 ◽  
Vol 444-445 ◽  
pp. 385-389 ◽  
Author(s):  
Ji Xiang Shan ◽  
Yong Huang ◽  
Xiao Yong Ma ◽  
Yong Hong Li ◽  
Jie Bai
Keyword(s):  
Lift Coefficient ◽  
Flow Characteristics ◽  
Aerodynamic Characteristics ◽  
Transition Model ◽  
Test Model ◽  
Layer Boundary ◽  
Simulation Research ◽  
Order Of Magnitude ◽  
Important Means ◽  
Flight Model

In wind tunnel tests, the size of the test model is generally much less than the real aircraft, which makes that the Re number during the test is an order of magnitude smaller than the flight Re number. The fixed transition is an important means to improve the test Re number. In the paper, the transition turbulence modelis used to simulate the flow characteristics of the test model (Re=1.5×106), flight model (Re=12×106) and fixed transition model. It is shows that the drag coefficient of the transition model increases and the lift coefficient decreases to compare with the test model and flight model. Compared with the flight model, the turbulent velocity profile of transition model in layer boundary is inadequate, its relative Re number is smaller, so the further amend in the aerodynamic characteristics need to be made.

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