A low-cycle fatigue approach to predicting shear strength degradation in RC joints subjected to seismic actions

The static and low cycle fatigue strength of an air plasma sprayed (APS) partially stabilized zirconia thermal barrier coating (TBC) is experimentally evaluated. The shear testing utilized the Iosipescu shear test arrangement. Testing was performed parallel to the TBC-substrate interface. The TBC testing required an innovative use of steel extensions with the TBC bonded between the steel extensions to form the standard losipescu specimen shape. The test method appears to have been successful. Fracture of the TBC was initiated in shear, although unconstrained specimen fractures propagated at the TBC-bond coat interface. The use of side grooves on the TBC was successful in keeping the failure in the gage section and did not appear to affect the shear strength values that were measured. Low cycle fatigue failures were obtained at high stress levels approaching the ultimate strength of the TBC. The static and fatigue strengths do not appear to be markedly different from tensile properties for comparable TBC material.

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A Shear Strength Degradation Model for Anisotropic Conductive Adhesive Joints Under Hygrothermal Conditions

Journal of Electronic Packaging ◽

10.1115/1.4025840 ◽

2013 ◽

Vol 135 (4) ◽

Author(s):

Bo Tao ◽

Guanghua Wu ◽

Zhouping Yin ◽

Youlun Xiong

Keyword(s):

Shear Strength ◽

Experimental Testing ◽

Theoretical Models ◽

Strength Degradation ◽

Conductive Adhesive ◽

Degradation Model ◽

Anisotropic Conductive Adhesive ◽

Degradation Data ◽

Shear Strength Degradation ◽

Relationship Of

Hygrothermal environments can degrade anisotropic conductive adhesive (ACA) joints by weakening the shear strength of adhesive interface. In this paper, the shear strength degradation model of ACA joints under hygrothermal conditions was formulated through experimental testing and theoretical modeling. The shear strength degradation data were obtained from different hygrothermal aging tests and the ACA moisture properties were characterized for the corresponding hygrothermal conditions. Theoretical models considering the hygrothermal factors of T (temperature), RH (relative humidity), and t (time), were used to fit the shear strength degradation data. It was found that the inverse exponential law was the best candidate model to predict the degradation data. The shear strength degradation model of ACA joints under hygrothermal conditions was proposed, where the relationship of the S (shear strength) and the hygrothermal factors (T, RH, and t) was expressed in an analytical model. The degradation model was validated by experiments, and the model predictions agreed well with the test results.

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Shear Strength Degradation of Pb-Free Solder Joint with Mounted Location in Automobile

MATERIALS TRANSACTIONS ◽

10.2320/matertrans.mi201420 ◽

2015 ◽

Vol 56 (7) ◽

pp. 1002-1006 ◽

Cited By ~ 1

Author(s):

Won Sik Hong ◽

A Young Kim

Keyword(s):

Shear Strength ◽

Solder Joint ◽

Strength Degradation ◽

Free Solder ◽

Shear Strength Degradation

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Runout simulation of seismic landslides using discontinuous deformation analysis (DDA) with state-dependent shear strength model

Canadian Geotechnical Journal ◽

10.1139/cgj-2019-0312 ◽

2020 ◽

Vol 57 (8) ◽

pp. 1183-1196 ◽

Cited By ~ 3

Author(s):

Ting-kai Nian ◽

Yan-jun Zhang ◽

Hao Wu ◽

Guang-qi Chen ◽

Lu Zheng

Keyword(s):

Shear Strength ◽

Strength Degradation ◽

Discontinuous Deformation Analysis ◽

Deformation Analysis ◽

State Dependent ◽

Discontinuous Deformation ◽

Landslide Process ◽

Global Safety Factor ◽

Seismic Landslide ◽

Shear Strength Degradation

The reliable numerical simulation of the landslide process contributes to the establishment of evidence-based disaster mitigation measures in seismically active zones. To achieve this goal, a simple and unified state-dependent shear strength model of discontinuities is presented to describe the shear strength degradation in a seismic landslide process. The proposed model establishes a relationship between the shear strength parameters and the global safety factor of the slope by assuming that the slope instability (or landslide initiation) is accompanied by an instantaneous shear strength degradation of discontinuities. To realize the model numerically, the algorithms for the computation of global safety factor and the modification of shear strength parameters were incorporated into the discontinuous deformation analysis (DDA). Subsequently, the kinematic accuracy of the improved DDA method was validated by comparisons with theoretical solutions for the dynamic sliding of a block on an inclined plane. Numerical simulations of the Daguangbao landslide triggered by the Wenchuan earthquake were performed using the improved DDA method. The results illustrate that the shear strength degradation of discontinuities affect the evolution process, travel distance, and post-failure shape of the seismic landslide significantly.

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