The role of mix design and short glass fiber content on mode-I cracking characteristics of polymer concrete

2022 ◽  
Vol 317 ◽  
pp. 126139
Author(s):  
M.R.M. Aliha ◽  
Hamid reza Karimi ◽  
Milad Abedi
Polymers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 969 ◽  
Author(s):  
Patrick Bradler ◽  
Joerg Fischer ◽  
Gernot Wallner ◽  
Reinhold Lang

Polyamide 66 (PA 66) and short glass fiber reinforced versions of PA 66 are widely used for solar-thermal applications, in which thermal and environmental loading of components is from high importance. In this study, the influence of crosslinking via electronic beam irradiation on the morphology and mechanical behavior of unreinforced PA 66 and two types of short glass fiber reinforced PA 66 (30 wt % glass fiber content, 35 wt % glass fiber content) was investigated. In total, five different electronic beam irradiation doses in the range of 0 and 200 kGy were applied. Besides experiments with unconditioned specimens, also preconditioned specimens saturated with water at 80 °C for seven days were investigated. It was found that irradiation causes a shift to lower melting temperatures and lower melting enthalpies, while simultaneously leading to higher glass transition temperatures (TG), increasing small strain modulus values and higher tensile strengths. Also, as expected, preconditioning samples in water at 80 °C to water uptake saturation leads to a shift to lower TG values (‘plasticization’ effect). In terms of tensile behavior at room temperature, water saturated specimens (being above TG at room temperature) exhibited lower modulus and tensile strength values compared to quasi-dry specimens (being below TG at room temperature).


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Senji Hamanaka ◽  
Chisato Nonomura ◽  
Thanh Binh Nguyen Thi ◽  
Atsushi Yokoyama

Abstract This study aims to clarify the relationship between the layer structure transition of fibers caused by the change in the flow field and the thermal properties and fiber interaction when the glass fiber content is changed. Polyamide 6 samples with different short glass fiber contents were prepared, and changes in layer structure during the flow process of injection molding were compared using X-ray computed tomography. An injection-molding simulation was performed to compare the changes in the layer structure of fibers during the flow process, and the temperature distribution and shear rate distribution were obtained by numerical analysis. Furthermore, the effect of fiber interaction on the layer structure transition of fibers was considered using a relaxation function composed of the fiber content, fiber shape factor, and strain rate.


2011 ◽  
Vol 181-182 ◽  
pp. 836-841
Author(s):  
Jiang Liu ◽  
Xiang Guo Liu

Influence of coupling agents on microstructure and mechanical properties of short glass fiber reinforced PA66 composites(SGF/PA66) were investigated by using twin screws extruder and injection machine in this paper. When coupling agents (A1100 or A1100+A+B) were added, short glass fiber was distributed in the PA66 matrix more homogeneously; at the same time, the microstructure and properties of GF/PA66 were improved too. Modified effect of multiple coupling agent (A1100+A+B) is better than that of only A1100 and the desired content of A1100 is about 1.5~2.0wt%. When glass fiber content was less than the critical value (35~40%), mechanical properties of PA composites increase with fiber content increasing, but it begin to decrease when content was excess that value. At last, Failure mechanism of GF/PA66 (treated by A1100 or A1100+A+B) was obtained: adhesion of interface between glass fiber and PA66 matrix, friction after the adhesion, glass fiber pullouted and matrix failure.


2022 ◽  
pp. 102599
Author(s):  
P. Ajith Kumar Jain ◽  
S. Sattar ◽  
D. Mulqueen ◽  
D. Pedrazzoli ◽  
S.G. Kravchenko ◽  
...  

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1569
Author(s):  
Selim Mrzljak ◽  
Alexander Delp ◽  
André Schlink ◽  
Jan-Christoph Zarges ◽  
Daniel Hülsbusch ◽  
...  

Short glass fiber reinforced plastics (SGFRP) offer superior mechanical properties compared to polymers, while still also enabling almost unlimited geometric variations of components at large-scale production. PA6-GF30 represents one of the most used SGFRP for series components, but the impact of injection molding process parameters on the fatigue properties is still insufficiently investigated. In this study, various injection molding parameter configurations were investigated on PA6-GF30. To take the significant frequency dependency into account, tension–tension fatigue tests were performed using multiple amplitude tests, considering surface temperature-adjusted frequency to limit self-heating. The frequency adjustment leads to shorter testing durations as well as up to 20% higher lifetime under fatigue loading. A higher melt temperature and volume flow rate during injection molding lead to an increase of 16% regarding fatigue life. In situ Xray microtomography analysis revealed that this result was attributed to a stronger fiber alignment with larger fiber lengths in the flow direction. Using digital volume correlation, differences of up to 100% in local strain values at the same stress level for different injection molding process parameters were identified. The results prove that the injection molding parameters have a high influence on the fatigue properties and thus offer a large optimization potential, e.g., with regard to the component design.


Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2250
Author(s):  
Mohammad Amjadi ◽  
Ali Fatemi

Short glass fiber-reinforced (SGFR) thermoplastics are used in many industries manufactured by injection molding which is the most common technique for polymeric parts production. Glass fibers are commonly used as the reinforced material with thermoplastics and injection molding. In this paper, a critical plane-based fatigue damage model is proposed for tension–tension or tension–compression fatigue life prediction of SGFR thermoplastics considering fiber orientation and mean stress effects. Temperature and frequency effects were also included by applying the proposed damage model into a general fatigue model. Model predictions are presented and discussed by comparing with the experimental data from the literature.


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