scholarly journals Coupled Hygro-Mechanical Finite Element Method on Determination of the Interlaminar Shear Modulus of Glass Fiber-Reinforced Polymer Laminates in Bridge Decks under Hygrothermal Aging Effects

Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 845 ◽  
Author(s):  
Xu Jiang ◽  
Chengwei Luo ◽  
Xuhong Qiang ◽  
Qilin Zhang ◽  
Henk Kolstein ◽  
...  

To investigate the mechanical degradation of the shear properties of glass fiber-reinforced polymer (GFRP) laminates in bridge decks under hygrothermal aging effects, short-beam shear tests were performed following the ASTM test standard (ASTM D790-10A). Based on the coupled hygro-mechanical finite element (FE) analysis method, an inverse parameter identification approach based on short-beam shear tests was developed and then employed to determine the environment-dependent interlaminar shear modulus of GFRP laminates. Subsequently, the shear strength and modulus of dry (0% Mt/M∞), moisture unsaturated (30% Mt/M∞ and 50% Mt/M∞), and moisture saturated (100% Mt/M∞) specimens at test temperatures of both 20 °C and 40 °C were compared. One cycle of the moisture absorption–desorption process was also investigated to address how the moisture-induced residual damage degrades the shear properties of GFRP laminates. The results revealed that the shear strength and modulus of moisture-saturated GFRP laminates decreased significantly, and the elevated testing temperature (40 °C) aggravated moisture-induced mechanical degradation. Moreover, an unrecoverable loss of shear properties for the GFRP laminates enduring one cycle of the moisture absorption–desorption process was evident.

2009 ◽  
Vol 610-613 ◽  
pp. 728-733 ◽  
Author(s):  
Yan Li ◽  
Feng Lv ◽  
Hong Xia Deng ◽  
Ronald Kollmansberger ◽  
Shan Ying Zeng

Interfacial properties of four kinds of natural fibers (et. ramie, jute, sisal and kenaf) reinforced phenolic resin were studied by single fiber pull-out test and short beam shear test. Effect of fiber surface treatments on the interfacial properties was evaluated. It showed that interlaminar shear strength (IFSS) was considerably improved after fiber surface treatments, especially after the silane treatment. Concerns about the poor moisture resistance of natural fibers, effects of fiber surface treatments on the moisture absorption behavior of natural fibers were also investigated by gravimetric methods. The results showed that neither fiber surface treatments nor the environmental temperature has effect on the moisture absorption behavior of natural fibers.


Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1874 ◽  
Author(s):  
Sian Wang ◽  
Yunhe Zhang ◽  
Gaohui Wu

This paper presents the effect of through-thickness reinforcement by steel z-pins on the interlaminar shear properties and strengthening mechanisms of carbon fiber reinforced aluminum matrix composites (Cf/Al) with a short beam shear test method. Microstructural analysis reveals that z-pins cause minor microstructural damage including to fiber waviness and aluminum-rich regions, and interface reaction causes a strong interface between the stainless steel pin and the aluminum matrix. Z-pinned Cf/Al composites show reduced apparent interlaminar shear strength due to a change in the failure mode compared to unpinned specimens. The changed failure mode could result from decreased flexural strength due to microstructural damage as well as increased actual interlaminar shear strength. Fracture work is improved significantly with a z-pin diameter. The strong interface allows the deformation resistance of the steel pin to contribute to the crack bridging forces, which greatly enhances the interlaminar shear properties.


2009 ◽  
Vol 79-82 ◽  
pp. 1779-1782 ◽  
Author(s):  
Zhen Xing Kong ◽  
Ji Hui Wang

To examine the role of nanoclays in the enhancement of interlaminar shear strength (ILSS) of glass fiber reinforced diallyl phthalate (GFR-DAP) composites, the GFR-DAP laminates were manufactured by hand lay-up techniques using two nanoclays, DK2 and MHAB-MMT, respectively. Χ-ray diffraction (XRD) were conducted to characterize the morphology of the dispersed clay particles in the DAP matrix. The mechanical performances were characterized by flexural strength and LISS measurements. XRD scans shows that the clays disperse uniformly in the DAP matrix and form an intercalated structure with a basal spacing of 3.86 nm and 3.98 nm for DK2 and MHAB-MMT, respectively. Short beam shear tests show that only 2.5 wt% clay loading in DAP matrix increased the ILSS of resulting GFR-DAP laminates by 7.64% and 14.80% for DK2 and MHAB-MMT, respectively, with respect to the neat DAP. The fractured surfaces of resulting laminates were observed by scanning electron microscope (SEM).


AIAA Journal ◽  
2002 ◽  
Vol 40 (11) ◽  
pp. 2368-2370
Author(s):  
Kunigal Shivakumar ◽  
Felix Abali ◽  
Adrian Pora

2018 ◽  
Vol 31 (7) ◽  
pp. 861-871
Author(s):  
Yixiang Zhang ◽  
Masahiko Miyauchi ◽  
Steven Nutt

The effects of thermal cycling on a polymerized monomeric reactant (PMR) type polyimide (TriA X) reinforced with carbon fibers were investigated. Composite specimens were subjected to 2000 thermal cycles between −54°C and 232°C. At 400-cycle intervals, laminates were inspected for microcracks, and glass transition temperature ( T g) and short-beam shear (SBS) strength were measured. The composites did not exhibit microcracks after thermal cycling, although after 2000 thermal cycles, mechanical properties of the matrix declined slightly. The matrix degradation decreased the resistance to microcracking upon further loading. No effects of thermal oxidative aging were observed from thermal cycling, and thermally driven fatigue and creep were identified as the primary and secondary factors inducing mechanical degradation of the matrix. T g of the composites exhibited no change after 2000 cycles, while the SBS strength decreased slightly (3–9%). The results highlight the potential for use of TriA X composites as long-term structural components in high-temperature service environments.


2020 ◽  
Vol 55 (1) ◽  
pp. 27-38
Author(s):  
Yasuka Nassho ◽  
Kazuaki Sanada

The purpose of this study is to improve interlaminar shear strength and self-healing efficiency of spread carbon fiber (SCF)/epoxy (EP) laminates containing microcapsules. Microencapsulated healing agents were embedded within the laminates to impart a self-healing functionality. Self-healing was demonstrated on short beam shear specimens, and the healing efficiency was evaluated by strain energies of virgin and healed specimens. The effects of microcapsule concentration and diameter on apparent interlaminar shear strength and healing efficiency were discussed. Moreover, damaged areas after short beam shear tests were examined by an optical microscope to investigate the relation between the microstructure and the healing efficiency of the laminates. The results showed that the stiffness and the apparent interlaminar shear strength of the laminates increased as the microcapsule concentration and diameter decreased. However, the healing efficiency decreased with decreasing the microcapsule concentration and diameter.


2005 ◽  
Vol 14 (4) ◽  
pp. 096369350501400
Author(s):  
Patrick Rosso ◽  
T. Tanimoto ◽  
Klaus Friedrich

In this study, the influence of piezoelectric ceramic particles (PZT) on a continuous carbon fibre (CF) reinforced epoxy was investigated. Therefore, unidirectional laminates were produced via film stacking in an autoclave. Mode-I interlaminar fracture toughness tests were carried out as well as tensile tests and short beam shear test to evaluate E-modulus and interlaminar shear strength (ILSS), respectively. The amount of PZT was varied and additional fracture surface analysis by scanning electron microscopy (SEM) clarified how the PZT affects the GIC of the particular laminates. It was found, that the addition of the PZT-particles caused a significant decrease in fracture toughness, whereas stiffness and ILSS were effected only marginally.


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