Study of the moisture/stress effects on glass fibre/epoxy composite and the impact of the interphase area

2014 ◽  
Vol 108 ◽  
pp. 876-885 ◽  
Author(s):  
Y. Joliff ◽  
W. Rekik ◽  
L. Belec ◽  
J.F. Chailan
Author(s):  
Sujith Bobba ◽  
Z Leman ◽  
ES Zainuddin ◽  
SM Sapuan

Consequences of sea water absorption on the impact behaviour of glass/epoxy composite elbow pipe joints were experimentally investigated. Glass-epoxy elbow pipe joints using E-glass and S-glass were fabricated via the hand layup method. The pipe joints were immersed in water as per the current conditions for 0, 3 and 6 months. The relation between the unaged and aged samples was studied by calculating the contact force, displacement and absorbed energy values from the impact tests. Therefore, it is concluded that sea water raised the ageing period of both E-glass/epoxy and S-glass/epoxy fibre-reinforced composite elbow pipe joints which resulted in the degradation between the fibre and resin interface and which was prominent in the elbow joints fabricated with E-glass rather than the one’s fabricated with the proposed S-glass fibre.


2021 ◽  
pp. 109963622199387
Author(s):  
Mathilde Jean-St-Laurent ◽  
Marie-Laure Dano ◽  
Marie-Josée Potvin

The effect of extreme cold temperatures on the quasi-static indentation and the low velocity impact behavior of woven carbon/epoxy composite sandwich panels with Nomex honeycomb core was investigated. Impact tests were performed at room temperature, –70°C, and –150°C. Two sizes of hemispherical impactor were used combined to three different impactor masses. All the impact tests were performed at the same initial impact velocity. The effect of temperature on the impact behavior is investigated by studying the load history, load-displacement curves and transmitted energy as a function of time curves. Impact damage induced at various temperatures was studied using different non-destructive and destructive techniques. Globally, more damages are induced with impact temperature decreasing. The results also show that the effect of temperature on the impact behavior is function of the impactor size.


2015 ◽  
Vol 825-826 ◽  
pp. 369-376 ◽  
Author(s):  
Robert Prussak ◽  
Daniel Stefaniak ◽  
Christian Hühne ◽  
Michael Sinapius

This paper focuses on the reduction of process-related thermal residual stress in fiber metal laminates and its impact on the mechanical properties. Different modifications during fabrication of co-cure bonded steel/carbon epoxy composite hybrid structures were investigated. Specific examinations are conducted on UD-CFRP-Steel specimens, modifying temperature, pressure or using a thermal expansion clamp during manufacturing. The impact of these parameters is then measured on the deflection of asymmetrical specimens or due yield-strength measurements of symmetrical specimens. The tensile strength is recorded to investigate the effect of thermal residual stress on the mechanical properties. Impact tests are performed to determine the influence on resulting damage areas at specific impact energies. The experiments revealed that the investigated modifications during processing of UD-CFRP-Steel specimens can significantly lower the thermal residual stress and thereby improve the tensile strength.


Weed Science ◽  
2018 ◽  
Vol 67 (1) ◽  
pp. 68-76 ◽  
Author(s):  
Nadeem Iqbal ◽  
Sudheesh Manalil ◽  
Bhagirath S. Chauhan ◽  
Steve W. Adkins

AbstractSesbania [Sesbania cannabina(Retz.) Pers.] is a problematic emerging weed species in Australian cotton-farming systems. However, globally, no information is available regarding its seed germination biology, and better understanding will help in devising superior management strategies to prevent further infestations. Laboratory and glasshouse studies were conducted to evaluate the impact of various environmental factors such as light, temperature, salt, osmotic and pH stress, and burial depth on germination and emergence of two Australian biotypes ofS. cannabina. Freshly harvested seeds of both biotypes possessed physical dormancy. A boiling-water scarification treatment (100±2 C) of 5-min duration was the optimum treatment to overcome this dormancy. Once dormancy was broken, the Dalby biotype exhibited a greater germination (93%) compared with the St George biotype (87%). The nondormant seeds of both biotypes showed a neutral photoblastic response to light and dark conditions, with germination marginally improved (6%) under illumination. Maximum germination of both biotypes occurred under an alternating temperature regime of 30/20 and 35/25 C and under constant temperatures of 32 or 35 C, with no germination at 8 or 11 C. Seed germination of both biotypes decreased linearly from 87% to 14% with an increase in moisture stress from 0.0 to −0.8 MPa, with no germination possible at −1.0 MPa. There was a gradual decline in germination for both biotypes when imbibed in a range of salt solutions of 25 to 250 mM, with a 50% reduction in germination occurring at 150 mM. Both biotypes germinated well under a wide range of pH values (4.0 to 10.0), with maximum germination (94%) at pH 9.0. The greatest emergence rate of the Dalby (87%) and St George (78%) biotypes was recorded at a burial depth of 1.0 cm, with no emergence at 16.0 cm. Deep tillage seems to be the best management strategy to stopS. cannabina’s emergence and further infestation of cotton (Gossypium hirsutumL.) fields. The findings of this study will be helpful to cotton agronomists in devising effective, sustainable, and efficient integrated weed management strategies for the control ofS. cannabinain cotton cropping lands.


2014 ◽  
Vol 564 ◽  
pp. 428-433 ◽  
Author(s):  
S.N.A. Safri ◽  
Mohamed Thariq Hameed Sultan ◽  
N. Razali ◽  
Shahnor Basri ◽  
Noorfaizal Yidris ◽  
...  

The purpose of this work is to study the best number of layer with the higher impact energy using Glass Fibre Reinforced Polymer (GFRP). The number of layers used in this study was 25, 33, 41, and 49. The impact test was performed using Single Stage Gas Gun (SSGG) for each layers given above with different bullets such as blunt, hemispherical and conical bullets. The gas gun pressure was set to 5, 10, 15 and 20 bar. All of the signals captured from the impact test were recorded using a ballistic data acquisition system. The correlation between the impact energy in terms of number of layer and type of bullet from this test are presented and discussed. It can be summarise that as the number of layer increases, impact energy also increases. In addition, from the results, it was observed that by using different types of bullets (blunt, hemispherical, conical), there is only a slight difference in values of energy absorbed by the specimen.


2020 ◽  
Vol 16 (2) ◽  
pp. 260-264
Author(s):  
H.Y. Patil ◽  
Pooja ◽  
V.P. Chimmad

The performance of crops need to be assessed for their production under erratic rain fall pattern, increased temperatures, and enhanced atmospheric CO2 concentration. In the present study groundnut was chosen as test crop and selected genotypes [four released (GPBD-4, G2-52, Dh-86 and TMV-2) and four pre-released (Dh-245, Dh-232, Dh-256 and Dh-257)] were studied to quantify the impact of moisture deficit stress at critical growth stages i.e., 40 to 80 DAS and 80 DAS to harvest. Leaf protein and proline increases in tolerant genotypes at higher moisture stress levels than susceptible genotypes as they acts as osmolytes and maintains the turgidity of the cell and hence, checks the water loss and peroxidase enzyme activity which in turn scavenges ROS produced due to stress as a result there was reduction in yield. The genotypes, GPBD-4, Dh-257 and Dh-256 recorded higher per cent increase in leaf soluble protein, leaf proline and peroxidase enzyme activity at all the stages. Increase was higher at 80 DAS to harvest stressed plants than 40 to 80 DAS stressed plants.


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