Experimental Study on New Low Cycle Fatigue Precision Cropping Process

2012 ◽  
Vol 48 (24) ◽  
pp. 38 ◽  
Author(s):  
Renfeng ZHAO
Keyword(s):  
Experimental Study ◽  
Low Cycle Fatigue ◽  
Cycle Fatigue

Experimental Study on Crack Propagation and Strain Accumulation of Cracked Stiffened Plate Under Cyclic Load

2018 ◽  
Author(s):  
Wei Jiang ◽  
Ping Yang ◽  
Ziya Peng
Keyword(s):  
Experimental Study ◽  
Fatigue Crack ◽  
Crack Propagation ◽  
Low Cycle Fatigue ◽  
Stiffened Plates ◽  
Strain Accumulation ◽  
Stiffened Plate ◽  
Cycle Fatigue ◽  
Fatigue Load ◽  
Cracked Structures

Stiffened plates with cracked damage are often subjected to constant amplitude and/or variable amplitude cyclic loads in sea environment. Under the stress-controlled asymmetric low-cycle fatigue loads, the coupling effect of low-cycle fatigue crack propagation and accumulative plasticity contributes to the increase of accumulative mean strain of cracked structures. Low-cycle fatigue crack growth and the increase of whole strain of cracked structures will change the bearing capacity of cracked structures. In this paper, experimental study on crack propagation and strain accumulation of cracked stiffened plate under low cycle fatigue load has been conducted. AH32 steel is used to make stiffened plate specimen with crack symmetrically located about stiffener. The accumulative strain of the cracked stiffened plate specimens during low-cycle fatigue crack propagation was obtained. From the experiments for cracked stiffened plates under the low-cycle fatigue loading, it is found out that the crack propagates firstly in the weld and then also gradually takes place in the stiffener. The stress ratio of low-cycle fatigue load and stiffener stiffness have been investigated in the experimental study and it is found out that these parameters significantly affect the low-cycle fatigue crack growth life and accumulation strain of the cracked stiffened plate specimens.

Buckling Restrained Brace With Inspection Windows

2015 ◽  
Author(s):  
C. S. Tsai ◽  
Yi Liu ◽  
B. Q. Liu
Keyword(s):  
Experimental Study ◽  
Energy Dissipation ◽  
Mechanical Behavior ◽  
Low Cycle Fatigue ◽  
Fatigue Tests ◽  
Test Results ◽  
Cycle Fatigue ◽  
Buckling Restrained Brace ◽  
Steel Core ◽  
Testing Protocols

The buckling restrained brace (BRB) has been worldwide recognized as an energy absorber to protect structures from earthquake damage. However, the traditional BRB is a fully close design, it is therefore impossible to detect the condition of the steel core during manufacturing and after earthquakes. This paper proposed a buckling restrained brace with inspection windows that allow inspecting the condition of the internal components of the BRB. Experimental study in selecting the sizes and locations of the inspection windows without affecting the functionality of the BRB has been carried out to search for an economically feasible BRB that is convenient for manufacturing and installation and meets testing protocols. Test results of the proposed BRBs under cyclic loadings showed that the mechanical behavior of the BRB with inspection windows on the buckling-restraining unit consisting of the constraining and lateral support elements was stable and that damage always occurred at the energy dissipation segments after low cycle fatigue tests. These test results indicate that the inspection windows opened on the proposed BRB have little influence on the strength of the device and that the proposed device can be considered as a stable energy dissipation device.

Experimental Study of Viscoelastic Dampers under Large Deformation

2012 ◽  
Vol 166-169 ◽  
pp. 2226-2233 ◽  
Author(s):  
Gang Zhao ◽  
Peng Pan ◽  
Jia Ru Qian ◽  
Jin Song Lin
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Energy Dissipation ◽  
Low Cycle Fatigue ◽  
Loss Modulus ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
Small Displacement ◽  
Loading Frequency ◽  
Cycle Fatigue

The paper presents an experimental study on a new type viscoelastic damper, which is expected to have better energy dissipation capability. Tests on the dampers’ mechanical properties, including shear storage modulus, shear loss modulus, and loss factor, were conducted using reduced scale specimens, and took strain amplitude, loading frequency and ambient temperature as test parameters. Aging tests, low cycle and high cycle fatigue tests were also conducted. Particularly, the low cycle fatigue behavior under a strain of 300% and the basic mechanical behavior under strains of 300%-420% were investigated. Test results suggest that the dependency of the mechanical properties on frequency and temperature is small, the energy dissipation capacity is stable for both large and small displacement, and the damper reaches a strain of 420% without failure.

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