Mechanical performance and crack retardation study of a fiberglass-grid-reinforced asphalt concrete system

2008 ◽  
Vol 35 (10) ◽  
pp. 1042-1049 ◽  
Author(s):  
S. Joon Lee
Keyword(s):  
Crack Propagation ◽  
Asphalt Concrete ◽  
Mechanical Performance ◽  
Fatigue Loading ◽  
Cyclic Fatigue ◽  
Mechanical Tests ◽  
Flexural Stress ◽  
Acrylic Polymer ◽  
Road Testing ◽  
Cracking Pattern

This paper presents constitutive design considerations for a semi-rigid, resin-impregnated fiberglass grid that enhances the mechanical performance of an asphalt concrete overlay and provides a pattern to retard crack propagation. An acrylic polymer resin covers the grid-structured fiberglass strands, thus making their viscoelastic nature compatible with the asphalt materials. The remarkable temperature susceptibility of the resin is observed using time–temperature superposition. The grid tensile strength of 100 kN/m was qualified using standard measurements. Three-point bending and cyclic fatigue loading mechanical tests affirm the retardation performance of the grid-reinforced system in terms of crack propagation. The retardation mechanism is affected by synchronizing the cracking pattern with the flexural stress–strain profile through image analysis. A National Center for Asphalt Technology full-scale road testing program provides assessment of the grid-reinforced pavements. A visual inspection of the grid extracted from the traffick zone showed fair condition of the pavement.

Static Fatigue Experimental Research on Orthotropic Deck with Composite Pavement Layer

2013 ◽  
Vol 275-277 ◽  
pp. 1011-1015
Author(s):  
De Rong Zhu ◽  
Zi Jiang Yang ◽  
Hui Zhang ◽  
Shi Zhong Liu ◽  
Gui Xia Ning
Keyword(s):  
Asphalt Concrete ◽  
Steel Fiber ◽  
Mechanical Performance ◽  
Fatigue Loading ◽  
Static Fatigue ◽  
Concrete Layer ◽  
Fiber Concrete ◽  
Steel Fiber Concrete ◽  
Loading Tests ◽  
Better Than

The experimental results show that the deck of the bridge displays obviously orthotropic features; shear nails with reasonable density can increase the binding capability of each part of deck pavement and overall mechanical performance. The results of fatigue test on the two groups of specimen indicate that the composite deck pavement added with the shear nails and the transition layer of steel fiber concrete has no sign of fatigue failure after 8.3 million fatigue loading tests, and its fatigue resisting property is obviously better than the deck pavement where the asphalt concrete is directly paved on the surface of deck, that is to say the service life of the deck pavement can be extended by the use of steel fiber concrete layer.

scholarly journals Mode I Crack Propagation Experimental Analysis of Adhesive Bonded Joints Comprising Glass Fibre Composite Material under Impact and Constant Amplitude Fatigue Loading

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4380
Author(s):  
Alirio Andres Bautista Villamil ◽  
Juan Pablo Casas Rodriguez ◽  
Alicia Porras Holguin ◽  
Maribel Silva Barrera
Keyword(s):  
Crack Propagation ◽  
Structural Integrity ◽  
Crack Propagation Rate ◽  
Fatigue Loading ◽  
Propagation Rate ◽  
Operating Conditions ◽  
Impact Testing ◽  
Mode I ◽  
Mode I Crack ◽  
Constant Amplitude

The T-90 Calima is a low-wing monoplane aircraft. Its structure is mainly composed of different components of composite materials, which are mainly bonded by using adhesive joints of different thicknesses. The T-90 Calima is a trainer aircraft; thus, adverse operating conditions such as hard landings, which cause impact loads, may affect the structural integrity of aircrafts. As a result, in this study, the mode I crack propagation rate of a typical adhesive joint of the aircraft is estimated under impact and constant amplitude fatigue loading. To this end, effects of adhesive thickness on the mechanical performance of the joint under quasistatic loading conditions, impact and constant amplitude fatigue in double cantilever beam (DCB) specimens are experimentally investigated. Cyclic impact is induced using a drop-weight impact testing machine to obtain the crack propagation rate (da/dN) as a function of the maximum strain energy release rate (GImax) diagram; likewise, this diagram is also obtained under constant amplitude fatigue, and both diagrams are compared to determine the effect of each type of loading on the structural integrity of the joint. Results reveal that the crack propagation rate under impact fatigue is three orders of magnitude greater than that under constant amplitude fatigue.

scholarly journals Preparation and Performance Evaluation of Duotone 3D-Printed Polyetheretherketone as Oral Prosthetic Materials: A Proof-of-Concept Study

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1949
Author(s):  
Ling Ding ◽  
Wei Lu ◽  
Jiaqi Zhang ◽  
Chuncheng Yang ◽  
Guofeng Wu
Keyword(s):  
Titanium Dioxide ◽  
Performance Evaluation ◽  
Mechanical Performance ◽  
Mechanical Tests ◽  
Flexural Properties ◽  
Proof Of Concept ◽  
Tooth Color ◽  
Dental Application ◽  
3D Printed ◽  
And Performance

Literature has reported the successful use of 3D printed polyetheretherketone (PEEK) to fabricate human body implants and oral prostheses. However, the current 3D printed PEEK (brown color) cannot mimic the vivid color of oral tissues and thus cannot meet the esthetical need for dental application. Therefore, titanium dioxide (TiO2) and ferric oxide (Fe2O3) were incorporated into PEEK to prepare a series of tooth-color and gingival-color PEEK composites in this study. Through color measurements and mechanical tests, the color value and mechanical performance of the 3D printed PEEK composites were evaluated. In addition, duotone PEEK specimens were printed by a double nozzle with an interface between tooth-color and gingival-color parts. The mechanical performance of duotone PEEK with two different interfaces (horizontal and vertical) was investigated. With the addition of TiO2 and Fe2O3, the colors of 3D printed PEEK composites become closer to that of dental shade guides. 3D printed PEEK composites generally demonstrated superior tensile and flexural properties and hence have great potential in the dental application. In addition, duotone 3D printed PEEK with a horizontal interfacial orientation presented better mechanical performance than that with a vertical one.

Microstructure analysis and mechanical performance of crumb rubber modified asphalt concrete using the dry process

2020 ◽  
Vol 259 ◽  
pp. 119662 ◽  
Author(s):  
Israel Rodríguez-Fernández ◽  
Farrokh Tarpoudi Baheri ◽  
Maria Chiara Cavalli ◽  
Lily D. Poulikakos ◽  
Moises Bueno
Keyword(s):  
Asphalt Concrete ◽  
Mechanical Performance ◽  
Crumb Rubber ◽  
Microstructure Analysis ◽  
Dry Process ◽  
Modified Asphalt

Analysis of Crack Propagation Behavior in Alumina with Different Grain Sizes under Static and Cyclic Fatigue

2004 ◽  
Vol 264-268 ◽  
pp. 793-796
Author(s):  
Hassan El Attaoui ◽  
Malika Saâdaoui ◽  
Jérôme Chevalier ◽  
Gilbert Fantozzi
Keyword(s):  
Crack Propagation ◽  
Cyclic Fatigue ◽  
Grain Sizes ◽  
Propagation Behavior ◽  
Crack Propagation Behavior

The Behavior of Tiled Laminate GFRP Composites, a Class of Robust Materials for Civil Applications

2019 ◽  
Author(s):  
Wouter De Corte ◽  
Jordi Uyttersprot ◽  
Wim Van Paepegem
Keyword(s):  
Crack Propagation ◽  
Numerical Simulations ◽  
Bridge Deck ◽  
Fatigue Loading ◽  
Structural Behavior ◽  
Gfrp Composites ◽  
Civil Structures ◽  
Laminate Composites ◽  
Deck Panels ◽  
Highly Loaded

<p>This paper focuses on the structural behavior of tiled laminate composites. Such laminates, in which the plies are not parallel to the outer surfaces are found in GFRP bridge deck panels. The technology is developed for the construction of robust GFRP panels useful in highly loaded structures such as bridges or lock gates. In civil structures, the drawback in traditional FRP sandwich structures has always been debonding of skin and core. Such a debonding problem may occur after unintentional impact, followed by fatigue loading. Through the concept of using overlapping Z-shaped and two-flanged web laminates, alternating with polyurethane foam cores, debonding is no longer possible in vacuum infused GFRP bridge deck panels. In such panels, the fibers in the upper and lower skins as well as in the vertical webs run in all directions, rendering a resin-dominated crack propagation impossible. As a result of the integration of core and skin reinforcement, a skin material is created in which the reinforcement is not parallel to the outer surfaces, but tiled. Based on experimental results and numerical simulations the relevance of tiled laminates for civil applications is demonstrated.</p>

New anterior controllable antedisplacement and fusion surgery for cervical ossification of the posterior longitudinal ligament: a biomechanical study

2022 ◽  
pp. 1-9
Keyword(s):  
Fatigue Loading ◽  
Axial Rotation ◽  
Posterior Longitudinal Ligament ◽  
Cyclic Fatigue ◽  
Biomechanical Study ◽  
Biomechanical Stability ◽  
Loading Test ◽  
Crossover Effect ◽  
Flexion Extension

OBJECTIVE The traditional anterior approach for multilevel severe cervical ossification of the posterior longitudinal ligament (OPLL) is demanding and risky. Recently, a novel surgical procedure—anterior controllable antedisplacement and fusion (ACAF)—was introduced by the authors to deal with these problems and achieve better clinical outcomes. However, to the authors’ knowledge, the immediate and long-term biomechanical stability obtained after this procedure has never been evaluated. Therefore, the authors compared the postoperative biomechanical stability of ACAF with those of more traditional approaches: anterior cervical discectomy and fusion (ACDF) and anterior cervical corpectomy and fusion (ACCF). METHODS To determine and assess pre- and postsurgical range of motion (ROM) (2 Nm torque) in flexion-extension, lateral bending, and axial rotation in the cervical spine, the authors collected cervical areas (C1–T1) from 18 cadaveric spines. The cyclic fatigue loading test was set up with a 3-Nm cycled load (2 Hz, 3000 cycles). All samples used in this study were randomly divided into three groups according to surgical procedures: ACDF, ACAF, and ACCF. The spines were tested under the following conditions: 1) intact state flexibility test; 2) postoperative model (ACDF, ACAF, ACCF) flexibility test; 3) cyclic loading (n = 3000); and 4) fatigue model flexibility test. RESULTS After operations were performed on the cadaveric spines, the segmental and total postoperative ROM values in all directions showed significant reductions for all groups. Then, the ROMs tended to increase during the fatigue test. No significant crossover effect was detected between evaluation time and operation method. Therefore, segmental and total ROM change trends were parallel among the three groups. However, the postoperative and fatigue ROMs in the ACCF group tended to be larger in all directions. No significant differences between these ROMs were detected in the ACDF and ACAF groups. CONCLUSIONS This in vitro biomechanical study demonstrated that the biomechanical stability levels for ACAF and ACDF were similar and were both significantly greater than that of ACCF. The clinical superiority of ACAF combined with our current results showed that this procedure is likely to be an acceptable alternative method for multilevel cervical OPLL treatment.

Development of Banana/Coir Natural Fibers Reinforced Polypropylene Hybrid Composites: The Effect of MA-g-PP (Maleic Anhydride Grafted Polypropylene) on Mechanical Properties and Thermal Properties

2021 ◽  
Vol 32 ◽  
pp. 85-97
Author(s):  
Gunturu Bujjibabu ◽  
Vemulapalli Chittaranjan Das ◽  
Malkapuram Ramakrishna ◽  
Konduru Nagarjuna
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Coupling Agent ◽  
Mechanical Performance ◽  
Hybrid Composites ◽  
Natural Fibers ◽  
Mechanical Tests ◽  
Coir Fiber ◽  
Banana Fiber ◽  
C Fibers

Banana/Coir fiber reinforced polypropylene hybrid composites was formulated by using twin screw extruder and injection molding machine. Specimens were prepared untreated and treated B/C Hybrid composites with 4% and 8% of MA-g-PP to increase its compatibility with the polypropylene matrix. Both the without MA-g-PP and with MA-g-PP B/C hybrid composites was utilized and three levels of B/C fiber loadings 15/5, 10/10 and 5/15 % were used during manufacturing of B/C reinforced polypropylene hybrid composites. In this work mechanical performance (tensile, flexural and impact strengths) of untreated and treated (coupling agent) with 4% and 8% of MA-g-PP B/C fibers reinforced polypropylene hybrid composite have been investigated. Treated with MA-g-PP B/C fibers reinforced specimens explored better mechanical properties compared to untreated B/C fibers reinforced polypropylene hybrid composites. Mechanical tests represents that tensile, flexural and impact strength increases with increase in concentration of coupling agent compared to without coupling agent MA-g-PP hybrid composites . B/C fibers reinforced polymer composites exhibited higher tensile, flexural and impact strength at 5% of Banana fiber, 15% of fiber Coir in the presence of 8% of MA-g-PP compared to 4% of MA-g-PP and untreated hybrid composites. The percentage of water absorption in the B/C fibers reinforced polypropylene hybrid composites resisted due to the presence of coupling agent MA-g-PP and thermogravimetry analysis (TGA) also has done.

scholarly journals Mechanical Performance Under Various Conditions of 3D Printed Polylactide Composites With Natural Fibers

2021 ◽  
Author(s):  
Karolina E. Mazur ◽  
Aleksandra Borucka ◽  
Paulina Kaczor ◽  
Szymon Gądek ◽  
Stanislaw Kuciel
Keyword(s):  
Elevated Temperatures ◽  
Mechanical Performance ◽  
Natural Fibers ◽  
Crystallization Rate ◽  
Mechanical Tests ◽  
Hydrothermal Degradation ◽  
3D Printed ◽  
The Impact ◽  
Different Levels ◽  
Additive Methods

Abstract In the study, polylactide-based (PLA) composites modified with natural particles (wood, bamboo, and cork) and with different levels of infilling (100%, 80%, and 60%) obtained by additive methods were tested. The effect of type fiber, infill level and crystallization rate on the mechanical properties were investigated by using tensile, flexural, and impact tests. The materials were subjected to mechanical tests carried out at 23 and 80 °C. Furthermore, hydrothermal degradation was performed, and its effect on the properties was analyzed. The addition of natural fillers and different level of infilling result in a similar level of reduction in the properties. Composites made of PLA are more sensitive to high temperature than to water. The decrease in Young's modulus of PLA at 80 °C was 90%, while after 28 days of hydrodegradation ~ 9%. The addition of fibers reduced this decrease at elevated temperatures. Moreover, the impact strength has been improved by 50% for composites with cork particles and for other lignocellulosic composites remained at the same level as for resin.

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