Comparing the Performance of Fiberglass Grid with Composite Interlayer Systems in Asphalt Concrete

2017 ◽  
Vol 2631 (1) ◽  
pp. 123-132 ◽  
Author(s):  
Andrew Wargo ◽  
Seyed Amirshayan Safavizadeh ◽  
Y. Richard Kim
Keyword(s):  
Double Layer ◽  
Asphalt Concrete ◽  
Fatigue Loading ◽  
Image Correlation ◽  
Control Mode ◽  
Correlation Technique ◽  
Interfacial Damage ◽  
Damage Mechanisms ◽  
Moisture Barriers ◽  
Comparison Of The Results

Geosynthetics, such as fabrics, grids, and composites, were introduced to asphalt pavements to mitigate reflective cracking or the creation of moisture barriers or both. Reinforcing interlayer systems, such as grids, have been shown to be effective in retarding the reflection of cracks in the underlying pavement into the upper layers. However, the effect of different interlayer systems on the performance of the pavement varies. The aim of this research was to compare the effects of fiberglass grids, paving fabric, and paving mat systems on the fatigue and fracture performance of double-layer beam specimens under four-point notched bending beam fatigue loading. Double-layer asphalt concrete beam specimens were loaded in a displacement control mode until full-depth cracking was observed. Haversine displacements with zero and maximum deflection peaks were applied to the specimens at frequencies of 5 and 10 Hz. The digital image correlation technique was used to determine and compare the damage mechanisms with stiffness curves plotted by using load and displacement data. A comparison of the results from beams with different interlayer systems showed that the type of interlayer system can noticeably affect the damage mechanisms and the performance of the fatigue specimen. In general, grid systems performed better when the interface bond was stronger. In nongrid interlayers, while interfacial damage created a discontinuity that increased the risk of interfacial debonding, a more flexible interlayer dissipated more energy at the interface and delayed the full vertical cracking of the beams under four-point bending beam fatigue loading.

scholarly journals Modeling of Bimodular Bone Specimen under Four-Point Bending Fatigue Loading

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 474
Author(s):  
Yufan Yan ◽  
Xianjia Meng ◽  
Chuanyong Qu
Keyword(s):  
Compressive Strain ◽  
Fatigue Loading ◽  
Degradation Process ◽  
Neutral Axis ◽  
Image Correlation ◽  
Bending Test ◽  
Correlation Technique ◽  
Fatigue Process ◽  
Four Point Bending ◽  
Bone Properties

The fatigue damage behavior of bone has attracted significant attention in both the mechanical and orthopedic fields. However, due to the complex and hierarchical structure of bone, describing the damage process quantitively or qualitatively is still a significant challenge for researchers in this area. In this study, a nonlinear bi-modulus gradient model was proposed to quantify the neutral axis skewing under fatigue load in a four-point bending test. The digital image correlation technique was used to analyze the tensile and compressive strains during the fatigue process. The results showed that the compressive strain demonstrated an obvious two-stage ascending behavior, whereas the tensile strain revealed a slow upward progression during the fatigue process. Subsequently, a theoretical model was proposed to describe the degradation process of the elastic modulus and the movement of the neutral axis. The changes in the bone properties were determined using the FEM method based on the newly developed model. The results obtained from two different methods exhibited a good degree of consistency. The results obtained in this study are of help in terms of effectively exploring the damage evolution of the bone materials.

scholarly journals Design Criteria for Scantling of Longitudinal and Transverse Connections in the Torsion Box Under Fatigue Loading

2021 ◽  
Vol 28 (2) ◽  
pp. 116-127
Author(s):  
Arturo Silva-Campillo ◽  
Juan Carlos Suárez-Bermejo ◽  
Miguel Ángel Herreros-Sierra
Keyword(s):  
Failure Modes ◽  
High Stress ◽  
Fatigue Loading ◽  
Image Correlation ◽  
Correlation Technique ◽  
Two Phase ◽  
High Stress Concentration ◽  
Phase Study ◽  
Propagation Law ◽  
Static Regime

Abstract Fatigue is one of the main failure modes in marine structures, and it is caused by the strong cyclic characteristics of the loads they support. This failure mode is amplified in areas of high stress concentration, such as at the intersection of primary and secondary elements. In this paper, a two-phase study is proposed that compares numerical and experimental results using a digital image correlation technique. The described procedure establishes selection, design, and scantling criteria and provides recommendations for the design of the transverse structure using specimens with different geometries. These geometries correspond to different designs for the transverse primary structure that use a longitudinal secondary stiffener with variable thickness and longitudinal spacing to transverse in a dynamic and quasi-static regime. The stress state for this regime is calculated based on the biaxiality indication concept, which uses the fatigue phenomenon (safety factor and sensitivity curves) and fracture mechanics (parameters of the Paris crack propagation law, correlation value, and law of variation of the stress intensity factor).

Durability of bonded assemblies A predictive theory coupling bulk and interfacial damage mechanisms

2009 ◽  
Vol 13 (9) ◽  
pp. 1141-1151
Author(s):  
Karim Benzarti ◽  
Pierre Argoul ◽  
Francesco Freddi ◽  
Michel Frémont ◽  
Thi Hoa Tam Nguyen
Keyword(s):  
Interfacial Damage ◽  
Damage Mechanisms ◽  
Predictive Theory

scholarly journals Design of a Unique Device for Residual Stresses Quantification by the Drilling Method Combining the PhotoStress and Digital Image Correlation

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 314
Author(s):  
Miroslav Pástor ◽  
Martin Hagara ◽  
Ivan Virgala ◽  
Adam Kaľavský ◽  
Alžbeta Sapietová ◽  
...  
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Experimental Testing ◽  
Digital Processing ◽  
Image Correlation ◽  
Optical Systems ◽  
Hole Drilling ◽  
Element Analysis ◽  
Thin Specimen ◽  
Comparison Of The Results

This paper presents a uniquely designed device combining the hole-drilling technique with two optical systems based on the PhotoStress and digital image correlation (DIC) method, where the digital image correlation system moves with the cutting tool. The authors aimed to verify whether the accuracy of the drilled hole according to ASTM E837-13a standard and the positioning accuracy of the device were sufficient to achieve accurate results. The experimental testing was performed on a thin specimen made from strain sensitive coating PS-1D, which allowed comparison of the results obtained by both methods. Although application of the PhotoStress method allows analysis of the strains at the edge of the cut hole, it requires a lot of experimenter’s practical skills to assess the results correctly. On the other hand, the DIC method allows digital processing of the measured data. However, the problem is not only to determine the data at the edge of the hole, the results also significantly depend on the smoothing levels used. The quantitative comparison of the results obtained was performed using finite element analysis.

Predicting strains in embedded reinforcement based on surface deformation obtained by digital image correlation technique

2021 ◽  
Author(s):  
Ali Mirzazade ◽  
Cosmin Popescu ◽  
Thomas Blanksvärd ◽  
Björn Täljsten
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Surface Deformation ◽  
Local Strain ◽  
Surface Strain ◽  
Image Correlation ◽  
Correlation Technique ◽  
Proposed Model ◽  
Structural Inspection ◽  
Semi Empirical

<p>This study is carried out to assess the applicability of using a digital image correlation (DIC) system in structural inspection, leading to deploy innovative instruments for strain/stress estimation along embedded rebars. A semi-empirical equation is proposed to predict the strain in embedded rebars as a function of surface strain in RC members. The proposed equation is validated by monitoring the surface strain in ten concrete tensile members, which are instrumented by strain gauges along the internal steel rebar. One advantage with this proposed model is the possibility to predict the local strain along the rebar, unlike previous models that only monitored average strain on the rebar. The results show the feasibility of strain prediction in embedded reinforcement using surface strain obtained by DIC.</p>

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