Experimental Research on Restoring Force Characteristics of Light Composite Structure

2011 ◽  
Vol 261-263 ◽  
pp. 130-136
Author(s):  
Sheng Сai Li
Keyword(s):  
Experimental Research ◽  
Composite Structure ◽  
Shear Force ◽  
Dynamic Test ◽  
Model Structure ◽  
Peak Acceleration ◽  
Base Shear ◽  
Restoring Force ◽  
Skeleton Curve ◽  
Static Test

Pseudo dynamic test and pseudo static test were carried out on 1/2 scale model of light composite structure. By experimental research, hysteretic curves of base shear force and top displacement of the model structure were got, which come from various sections of pseudo dynamic test and pseudo static test, and through hysteretic curves of base shear force and top displacement of the model structure, skeleton curve of base shear force and top displacement of the model structure can be got. Outside line of all skeleton curves was skeleton curve of the light composite structure model. By analyzing and simplifying of the skeleton curve, finally restoring force model of the model structure was obtained, so reasonable dynamic analysis method of seismic design of the model structure can be offered. Research shows that as peak acceleration of inputting seismic wave continuously grows, especially when the peak acceleration reaching 800 gal, after the model structure reached plastic stage and in the stage of pseudo static test, the hysteretic curves become fuller and fuller, which shows that, with continuous emerging and propagation of crack, the structural rigidity losses gradually, and its energy dissipation capacity increases gradually. So earthquake fortification level of not collapse when hit by rarely occurred earthquake will achieve.

Experimental Study for Seismic Performance of Confined Masonry Structure

2013 ◽  
Vol 353-356 ◽  
pp. 1826-1831
Author(s):  
Tie Jun Qu ◽  
Yan Ping Wang ◽  
Xian Yun Wang
Keyword(s):  
Seismic Performance ◽  
Dynamic Test ◽  
Hysteresis Loops ◽  
Structural Response ◽  
Time History ◽  
Design Code ◽  
Restoring Force ◽  
Static Test ◽  
Confined Masonry ◽  
Made In

A two-story masonry housing model was made in this paper. According to Intensity 7, adjusted Northridge record was selected to be the ground motion input in the pseudo-dynamic test. Pseudo-dynamic test and pseudo-static test were carried out to investigate the seismic behavior of the model structure. The time-history curves of the acceleration, velocity, displacement and restoring force of the structural response were obtained besides the time-history curves of the measuring points of the structure. Also the steel strain of the tie-columns and the hysteresis loops of the structure were obtained. The result shows multi-story confined masonry structures possess superior seismic performance if coordinated with the provision specified in the current compulsory design code and it can continue to use after appropriate dressing under the rarely earthquake.

Seismic Performance Experimental Research of Added Ring-Beams and Tie-Columns Masonry Structure

2013 ◽  
Vol 368-370 ◽  
pp. 1747-1755
Author(s):  
Tie Jun Qu ◽  
Jing Yi Chen ◽  
Xian Yun Wang
Keyword(s):  
Seismic Performance ◽  
Dynamic Test ◽  
Time History ◽  
Masonry Structure ◽  
Displacement Curve ◽  
Restoring Force ◽  
Static Test ◽  
Capacity Limit ◽  
Force Displacement ◽  
Ultimate Limit

To research seismic performance of the strengthened masonry structure, the two stories masonry structure housing model with added ring-beams and tie-columns was designed and made in this paper. By inputting acceleration time-history curve of rarely earthquake of Intensity 7, the seismic response of acceleration, speed, restoring force and displacement of the strengthened masonry structure were obtained through the pseudo-dynamic test when rarely earthquake of Intensity 7 occurred. The reinforcement strain time-history curves of tie-columns root and beam-column junction were tested, then the restoring force-displacement curve of the structure was obtained. By method of pseudo-static test, the strengthened masonry structure of the ultimate limit bearing capacity, limit deformation were obtained, the cracking part and developing process were observed. Finally, comparing the data in this test with that test result of the ring-beams and tie-columns masonry structure designed based on current codes; analyzed seismic performance of the strengthened masonry structure when rarely earthquake of Intensity 7 occurred.

An Agricultural Vehicle Frame Load Characteristic Agricultural Experimental Research

2014 ◽  
Vol 1006-1007 ◽  
pp. 47-50
Author(s):  
Zhong Ke Xiang ◽  
Fei Fei Xiang ◽  
Hua Zhong Wang
Keyword(s):  
Data Analysis ◽  
Experimental Research ◽  
Dynamic Load ◽  
Dynamic Stress ◽  
Dynamic Test ◽  
Electrical Measuring ◽  
Test Load ◽  
Static Test ◽  
Static Data ◽  
Actual Stress

Assess the actual stress situation by electrical measuring test of prototypes in the Milford Proving Ground, Including four cylinder engine bend and torsion static test load 10 t, 17t ; Proving ground inland various pavement dynamic test, According to the static data analysis results, the stress mainly concentrated in the cab and carriages, there is also the location of the crack appears most, and each point in the dynamic test of dynamic load is large, dynamic stress is one of the largest in the washboard road test.

scholarly journals Effect of Bottom Geometry on the Natural Sloshing Motion of Water Inside Tanks: An Experimental Analysis

2021 ◽  
Vol 11 (2) ◽  
pp. 605
Author(s):  
Antonio Agresta ◽  
Nicola Cavalagli ◽  
Chiara Biscarini ◽  
Filippo Ubertini
Keyword(s):  
Energy Dissipation ◽  
Water Depth ◽  
Shear Force ◽  
Experimental Tests ◽  
Shear Load ◽  
Damping Properties ◽  
Base Shear ◽  
Structure Interaction ◽  
Sloshing Phenomenon ◽  
Key Aspects

The present work aims at understanding and modelling some key aspects of the sloshing phenomenon, related to the motion of water inside a container and its effects on the substructure. In particular, the attention is focused on the effects of bottom shapes (flat, sloped and circular) and water depth ratio on the natural sloshing frequencies and damping properties of the inner fluid. To this aim, a series of experimental tests has been carried out on tanks characterised by different bottom shapes installed over a sliding table equipped with a shear load cell for the measurement of the dynamic base shear force. The results are useful for optimising the geometric characteristics of the tank and the fluid mass in order to obtain enhanced energy dissipation performances by exploiting fluid–structure interaction effects.

The effect of element strength assignment on the torsional response of stiffness-eccentric systems

2013 ◽  
Vol 40 (7) ◽  
pp. 655-662
Author(s):  
George K. Georgoussis
Keyword(s):  
Structural Design ◽  
Shear Force ◽  
Ground Motions ◽  
Building Structures ◽  
Centre Of Mass ◽  
Base Shear ◽  
Structural Behaviour ◽  
Torsional Response ◽  
Building Models ◽  
Storey Building

Building structures of low or medium height are usually designed with a pseudostatic approach using a base shear much lower than that predicted from an elastic spectrum. Given this shear force, the objective of this paper is to evaluate the effect of the element strength assignment (as determined by several building codes) on the torsional response of inelastic single-storey eccentric structures and to provide guidelines for minimizing this structural behaviour. It is demonstrated that the expected torque about the centre of mass (CM) may be, with equal probability, positive (counterclockwise) or negative (clockwise). This result means that the torsional strength should also be provided in equal terms in both rotational directions, and therefore the base shear and torque (BST) surface of a given system must be symmetrical (or approximately symmetrical). In stiffness-eccentric systems, appropriate BST surfaces may be obtained when a structural design is based on a pair of design eccentricities in a symmetrical order about CM, and this is shown in representative single-storey building models under characteristic ground motions.

Research on Numerical Integration Algorithm for MDOF Pseudo-Dynamic Test

2012 ◽  
Vol 204-208 ◽  
pp. 4820-4826
Author(s):  
Xin Guo ◽  
Li Hua Zhu ◽  
Tian Li Wang
Keyword(s):  
Dynamic Test ◽  
Experimental System ◽  
Test System ◽  
Unconditional Stability ◽  
Comparison Study ◽  
Restoring Force ◽  
Integration Algorithm ◽  
Integration Algorithms ◽  
Simulation Results ◽  
Force Characteristics

This paper focuses on two integration algorithms used for pseudo-dynamic test, explicit Newmark algorithm and implicit alpha-C algorithm. The comparison study between the test and simulation results shows that: the non-uniform distribution of mass, restoring force characteristics and higher frequency vibration modality are simulated more accurately using the alpha-C algorithm than using explicit Newmark algorithm. The alpha-C algorithm also leads to high iterative accuracy and unconditional stability. Replacing the explicit Newmark algorithm in original experimental system by implicit alpha-C algorithm, the MDOF pseudo dynamic test system can be realized successfully.

Dynamic Fracture Toughness Testing for Welding Part of Nuclear Piping Using Normalization Data Reduction Technique

2006 ◽  
Vol 306-308 ◽  
pp. 73-78
Author(s):  
Yong Huh ◽  
Hyung Ick Kim ◽  
Chang Sung Seok
Keyword(s):  
Fracture Toughness ◽  
Dynamic Fracture ◽  
Data Reduction ◽  
Dynamic Test ◽  
Dynamic Fracture Toughness ◽  
Reduction Technique ◽  
Fracture Toughness Test ◽  
Static Test ◽  
Welding Part ◽  
Data Reduction Technique

In this study, we performed the static test of nuclear piping materials by the unloading compliance method and the normalization data reduction technique and obtained two fracture resistance curves (J-R curves). The two curves were similar, which proves that the normalization data reduction technique can be adopted in the static test. Then we performed the dynamic fracture toughness test for welding part of nuclear piping. The J-R curves were obtained from the dynamic test by the normalization data reduction technique and were compared to those of the static test results.

scholarly journals Lengthening But Not Shortening History of Paraspinal Muscle Spindles in the Low Back Alters Their Dynamic Sensitivity

2011 ◽  
Vol 105 (1) ◽  
pp. 434-441 ◽  
Author(s):  
Dong-Yuan Cao ◽  
Joel G. Pickar
Keyword(s):  
Spinous Process ◽  
Dynamic Test ◽  
Muscle Spindles ◽  
Intermediate Position ◽  
Paraspinal Muscle ◽  
Low Back ◽  
Mean Velocity ◽  
Static Test ◽  
Velocity Sensitivity ◽  
Movement History

Proprioception is considered important for maintaining spinal stability and for controlling posture and movement in the low back. Previous studies demonstrate the presence of thixotropic properties in lumbar muscle spindles, wherein a vertebra's positional history alters spindle responsiveness to position and movement. This study investigated whether a vertebra's movement history affects the velocity sensitivity of paraspinal muscle spindles in the low back. Afferent activity from multifidus and longissimus muscle spindles was recorded in the L6 dorsal root in 30 anesthetized cats. To alter movement history, a feedback-controlled motor attached to the L6 spinous process held (conditioned for 4 s) the L6 vertebra at an intermediate position or at positions that either lengthened or shortened the muscles. With the vertebra returned to the intermediate position, resting spindle discharge was measured over the next 0.5 s (static test) and then during a dynamic test consisting of ramp vertebral movement at four velocities (0.2, 0.5, 1.0, 2.0 mm/s). Spindle activity during the tests was measured relative to hold-intermediate. For both tests, hold-long decreased and hold-short increased muscle spindle responsiveness. For the static test position responsiveness was not different among the velocity protocols for either hold-long or hold-short ( P = 0.42 and 0.24, respectively). During the dynamic test, hold-long conditioning significantly decreased [ F(3,119) = 7.99, P < 0.001] spindle responsiveness to increasing velocity. Mean velocity sensitivity was 4.44, 3.39, and 1.41 (impulses/s)/(mm/s) for the hold-short, hold-intermediate, and hold-long protocols, respectively. The nearly 2.5-fold decrease in velocity sensitivity following hold-long was significantly less than that for either hold-intermediate ( P = 0.005) or hold-short conditioning ( P < 0.001). Hold-short conditioning had little effect on velocity responses during the dynamic test [ F(3,119) = 0.23, P = 0.87]. In conclusion, only movement histories that stretch but not shorten muscle spindles alter their velocity sensitivity. In the low back, forward flexion and lateral bending postures would likely be the most provocative.

Reliability Evaluation and Study of Static and Dynamic Load Tests of Long Span Continuous Bridge with Variable Section

2011 ◽  
Vol 374-377 ◽  
pp. 2411-2420
Author(s):  
Sui Tan ◽  
Zhi Wu Yu ◽  
Hua Shuai Zhang
Keyword(s):  
Evaluation Method ◽  
Concrete Strength ◽  
Dynamic Test ◽  
Reliability Evaluation ◽  
Scientific Basis ◽  
Static Test ◽  
Long Span ◽  
Variable Section ◽  
Load Tests ◽  
Relationship Of

The reliability evaluation for the bridge in service can provide a scientific basis for decision-making in bridge repair and reinforcement. A comprehensive method for reliability evaluation was introduced in this paper based on a long span continuous bridge with variable section evaluation. Appearance survey of the bridge, concrete strength and carbonization test, static test and dynamic test would be done as well as the finite element simulation model to determine the properties of the bridge for reliability evaluation. The relationship of the natural frequency stiffness evaluation method and the effective coefficient method would be established in this paper based on the test results. Based on the static and dynamic test, we classify the bridge as class 3 while the bending stiffness is good, the dynamic rigidity is a little weak, and the damping coefficient a little larger.

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