Introduction
A composite is a combination of two or more materials with distinctive physical and chemical properties [1]. The structure of a composite consists of a matrix phase that can be a polymer, metal, or ceramic, as well as a reinforcement phase, which includes micro- or nanoparticles or fibers. The physical and mechanical properties of the composites are influenced by factors such as the size and shape of the materials, the type of base material and reinforcement, and the proper distribution and bonding with the base material [2]. Polymer-based composites have several advantages over metal-based composites and concrete parts, such as light weight, corrosion resistance, and fatigue resistance, which has led to their widespread use in industry. One of the most beneficial composites is composed of a polymer and resin base reinforced by fibers. In this blend, fibers play a crucial role in load and force bearing. The polymer matrix binds the fibers and protects them against chemical and physical damage, while also transferring load [3]. The composite with unidirectional continuous fibers is rigid in the direction of the fibers but weak in the direction perpendicular to the fibers. The more random the direction of the fibers, the more random the properties of the composite. Among the most important composites in the industry are glass fiber-reinforced composites, which have high tensile strength, low weight, and lower prices than fibers like carbon or Kevlar [3, 4]. The appropriate bonding and performance between glass fibers and resin material, along with the absence of porosity, improve the properties of the composite [4]. The resin transfer molding (RTM) is a closed-mold fabrication process that employs polymers such as epoxy and vinyl ester and reinforces them with various fibers to produce composite parts with high surface roughness and precision [5, 6]. The RTM method involves laying the reinforcement into the mold, arranging the fibers, and then injecting the polymer base material to cover the fibers. The curing process is then carried out to establish strength and an appropriate bond between the resin and the fibers. This method produces composite samples with minimal lamination flaws and speeds up production through a more streamlined process, requiring less manual labor [7].
The introduction of holes within composite plates induces stress concentration, thereby influencing the failure mode, mechanical strength, and layers properties of the composite plate. The specific shape and arrangement of the holes play a crucial role in determining the extent of these effects on the plate's failure behavior and overall mechanical properties. An extensive body of literature exists, wherein the properties and strength of composite plates have been thoroughly investigated. Cunningham et al. [8] conducted experimental research to explore the effect of hole position on glass fiber-reinforced polymeric composites on both mechanical strength and crack propagation characteristics. Different samples were created with varying thicknesses and different numbers and distances of holes. The findings revealed that the material's strength significantly decreases when it contains a circular hole. However, the presence of additional holes does not further worsen this strength reduction. El-sisi et al. [9] analyzed the bonding strength of composite plates containing holes, where specific apertures were introduced and securely fastened using screws from below. Subsequently, tensile tests were conducted on the assembled specimens to assess their connection performance. The experimental results indicated that both the distance between the holes and the number of holes have a notable impact on the maximum load the material can bear. Additionally, the arrangement of the holes was observed to cause significant bending in the out-of-plane direction. Kang et al. [10] performed comprehensive analytical and theoretical examinations to study the impact of a single hole in a composite plate on the buckling behavior of the sample. The obtained results were consistent, showing that when damage initiated at the edge of a hole, it spread to both sides, first affecting the matrix, and then leading to damage in the fibers. Supar et al. [11] employed 2D finite element simulation to investigate the tensile strength and properties of fiber-reinforced composite plates. The simulations involved samples with varying numbers and arrangements of holes to explore their influence on the mechanical behavior of the plates. The investigation revealed that in non-staggered hole configurations, the highest stress levels were observed at the outer holes. This suggests that net-sectional failure was initiated at those points, and the cracks propagated in a self-similar manner throughout the plate thickness. Mortazavi et al. [12] investigated the effect of the fiber direction and temperature on the tensile strength and elastic modulus in polybutylene terephthalate (PBT) and polyamide-6 (PA6)-based composites, reinforced with glass fibers by the RTM method. SEM images showed the fracture of samples in three directions, including parallel to the fibers, perpendicular to the fibers, and aligned with the applied load.
In another study, Cordin et al. [13] produced polymer composite samples by reinforcing them with various fibers arranged at different angles, ranging from 0° to 90° with an increment of 22.5°. The results of tensile tests indicated that the samples with fibers at a 45° angle had the best ultimate tensile strengths and highest maximum toughness. Sikarwar et al. [14] produced samples using the RTM method and reinforced them with glass fibers in different directions and thicknesses. The results of the impact test showed that polymer composites reinforced with thinner glass fibers had the strongest bond with the resin and, thus, exhibited the greatest impact strength. In addition, the impact resistance of the samples increased when the impact test was conducted at a higher strain rate. Tambora et al. [15] produced polymer composite plates that were reinforced with short and chopped glass fibers. They investigated the effect of the temperature on the fatigue strength and durability of the RTM samples and examined the microstructure of the fracture by SEM photography of the fracture cross sections. Jiang et al. [16] produced composite sandwich panels by the RTM method in different thicknesses and arrangements of glass fibers and subjected them to mechanical tests, including tensile, bending, and impact tests. Investigations into the fracture and the cross-section of the samples revealed that the central core plate underwent plastic deformation and an increase of 0.25 mm in thickness resulted in a 23% rise in bending strength. Sebaey et al. [17] produced polymer composites with polyurethane foams and reinforced them with carbon fibers. They successfully increased the impact resistance and energy absorption to 75 J.
Francioso et al. [18] conducted a study in which polymer samples made of polypropylene were produced, and they were reinforced with varying percentages of glass fibers (ranging from 0 to 15%) at different temperatures. Bending tests were then performed to determine the fracture load, toughness and adhesion of layers together. The best result was obtained for the sample with 10% glass fibers at a temperature of 200 °C. Rahimzadeh et al. [19] produced composite wind turbine blades with a 5 wt% glass fiber reinforcement using the RTM method. The tensile test results demonstrated that the addition of the glass fibers to the base material improved the elastic modulus and ultimate strength by 16% and 10%, respectively. Using the RTM method, Ebadzadeh et al. [20] produced pipes made of polyester and epoxy resin and reinforced with glass fibers. The corrosion test was carried out to assess the pipes' behavior towards corrosion in hydrochloric acid, sulfuric acid, and sodium chloride. The findings showed that the corrosion resistance of polymer composites with polyester as the base material was inferior compared to those with epoxy resin in all tested environments. Liuyang et al. [21] used both the cold working method and the RTM method to produce samples made of Ti-6Al-4 V. They ran a high-temperature corrosion test under air conditions at a temperature of 60ºC. The RTM method resulted in a sample with a higher weight compared to the other method, due to its lower levels of porosity and delamination. The corrosive environment containing sulfur increased the corrosion rate and decreased the corrosion resistance. San et al. [22] produced the polymer samples reinforced with basalt fibers and concrete using the RTM method. They studied the strength and the bond between the fibers and the base resin. The results showed that the RTM method enhanced the strength and adhesion of the samples.
For the assembly and installation of composite plates and components, the incorporation of holes and grooves is necessary, even though they can be created during servicing [23]. Analyzing and studying the ultimate strength or load-bearing capacity of composite plates with holes is crucial for their application in various industries [24]. Although extensive research exists on the strength of polymeric or metal composites with a single notch or hole, the majority of these studies concentrate on plates with either a single hole or no hole at all. Notably, the potential failure mechanisms resulting from multiple holes have not been thoroughly investigated in the existing literature. In the present study, we experimentally analyzed the strength of composite plates with multiple holes, which were produced using the RTM method. By examining the behavior of such hole-containing composite plates, we aim to provide valuable insights into their mechanical properties and potential performance under various loading conditions.
The current study involved the production of 5-layer composite plates using the RTM method, with polyester resin as the base material and glass fibers as the reinforcement with a 55 wt% resin and 45 wt%. The ballistic limit of the RTM sample was initially examined to determine its speed and pressure limit. To assess the impact of hole drilling on the mechanical properties of the plates, tensile, bending, and impact strength tests were performed on samples with no holes (G0), three holes (G3), and five holes (G5).
Experimental Procedure
The RTM method utilizes molds that consist of both a solid and a flexible component, with the fiber layers being arranged by hand. The arrangement of the fibers is shown in Fig. 1. A coating gel is used in one layer to optimize the quality of the surface and better separate the final part from the mold. Next, the fiber arrangement was accomplished using mat 300 fabric for the outermost layers, followed by the placement of woven glass fibers 600 at angles of (+ 45°, -45°). Finally, mat 300 was placed in the middle layer. The fiber placement technique aims to ensure the highest possible adhesion and bonding of the fibers to the gelcoat [25].
Fig. 1 [Images not available. See PDF.]
The schematic of the RTM method and the arrangement of the 5-layered composite plate
Once the layers were laid up, the mold was closed with the help of gravity and minor vibrations, and then sealed. Subsequently, pressure was applied to the samples by utilizing a relative vacuum. At this moment, isophthalic-saturated polyester resin was injected into the mold with a constant pressure of 500 kPa. To enhance strength and cohesion, cobalt and acid peroxide were added to the polyester resin in proportions of 1.5 wt% and 1 wt%, respectively, and the mixture was stirred for 45 min. The resin-to-glass fibers ratio is 1.2, meaning that for the 45% weight percentage of glass fibers, 55% weight percentage of resin was utilized for molding. Following the injection and escape of the resin from the opposite side of the mold, it was clear that the resin had penetrated into the mold and infused between the fibers. Subsequently, the materials gelled for 22 min at 25 °C. The heating continued for 3 h in the oven, and the baking process was completed at 80 °C. After the completion of the baking process, 5-layered composite plates, reinforced with glass fibers, were produced with a thickness of 4 mm. Samples measuring 50 × 100 mm were cut for tensile and bending tests, and samples measuring 100 × 100 mm were cut for impact and ballistic tests [26]. The ballistic limit of the produced samples was determined through a ballistic test carried out using a gas gun. The bullets were propelled by air and were fired at varying speeds and pressures to fix the bullet onto the plate. The bullet used in the ballistic test was made of hardened steel and was designed with a sharp conical tip. It weighed 9.33 g and had a diameter of 9 mm and a length of 16.8 mm. The fixture consisted of two steel plates with dimensions of 40 × 40 mm and a thickness of 20 mm, around which 8 holes with a diameter of 20 mm were drilled to fasten the samples with bolts and nuts. The pictures of the process, the device, the bullet used, and the fixture used to secure the samples during the test are shown in Fig. 2.
Fig. 2 [Images not available. See PDF.]
(a) The mold used for ballistic test, (b) the samples on the mold, and (c) the bullet
Figure 3 depicts the schematic diagram of the ballistic test, wherein the pressure of pressurized tank is measured using a pressure gauge. Optical sensors are employed to calculate the velocities before and after the impact. To calibrate the ballistic device and establish the relationship between bullet speeds and firing pressures, a series of bullets were fired at an aluminum plate under varying pressures. Through analysis of the collected data encompassing diverse pressures and velocities, Eq. (1) was derived. The equation expresses the relationship between speed (V) and pressure (P), measured in m/s and bar, respectively. The diagram corresponding to the equation is presented in Fig. 4.
1
Fig. 3 [Images not available. See PDF.]
The schematic diagram of the ballistic test
Fig. 4 [Images not available. See PDF.]
Calibration data for the used bullet
In this study, the interconnection of composite plates is achieved through drilling, bolting, and the use of nuts, since the use of welding or soldering techniques is restricted in this specific context or for the given materials. Consequently, the creation of holes during the production process or molding becomes necessary, although it may present challenges and incur costs. The number and arrangement of these holes can significantly influence the ultimate strength and crack propagation behavior between them. Moreover, as the holes are often positioned at the edges of the composite plates and follow a repetitive pattern, their structural impact becomes crucial. The present manuscript investigates the effects of two different types of holes on the strength characteristics of the composite plates. To investigate the effect of hole drilling on tensile, bending, and impact strength, three holes with a diameter of 10 mm were drilled into some samples and five holes with the same diameter were drilled into others. The surface of a cross section of a manufactured sample and the dimensions and locations of the drilled holes can be seen in Fig. 5. It is notable that the glass fibers are not visible due to their low thickness and being embedded in resin during the baking process.
Fig. 5 [Images not available. See PDF.]
(a) The cross-section of the produced sample, (b) the schematic of the G3 sample, (c) the schematic of the G5 sample
For the tensile test, the samples were clamped between two jaws and subjected to the tensile test at a strain rate of 5 mm/min [4]. The images of the samples for the tensile and bending tests, which were mounted inside the testing equipment, are shown in Fig. 6. A graph was generated showing the relationship between fracture force and strain as the samples underwent a bending test with a strain rate of 5 mm/min and a support distance of 80 mm.
Fig. 6 [Images not available. See PDF.]
The samples for the tensile and bending tests: (a) G0, (b) G3, (c) G5, (d) the setup for conducting a tensile test, and (e) the setup for conducting a bending test
The fracture energy and brittle behavior of the samples were determined through impact testing, by striking them with a hammer. The tests were carried out in accordance with ASTM D256 by dropping a 27 kg cylindrical weight with a diameter of 11.4 mm from a height of 0.6 m at a speed of 3.5 m/s [27]. Figure 7 displays the images of the samples and the test conditions.
Fig. 7 [Images not available. See PDF.]
The samples for impact test (a) G0, (b) G3, (c) G5, (d) the method for conducting an impact test, and (e) the hammer used
Results and discussions
The Ballistic Limit Test
The samples with a thickness of 4 mm and a size of 50 × 50 mm were placed inside molds for testing. The bullet was then shot at the samples with varying speeds and pressures multiple times. The results of the testing are given in Table 1. In the first experiment, firing the bullet at the sample with a pressure of 2 bar and a speed of 40 m/s had no effect. Similarly, when the bullet was shot again with a pressure of 2.5 bar and a speed of 45 m/s, there was no change in the sample. However, in the third attempt, a 58% increase in pressure to 6 bar and a speed of 80 m/s led to the stripping of the gel coat layer from the surface and left it behind scratches. The fourth test, which was conducted with a speed of 108 m/s and a pressure of 12 bar, resulted in the creation of a hole in the sample, with the bullet passing through it. The objective of the experiment was to reach the ballistic limit, which required the bullet to pass through 50% of the sample. In the fifth test, the pressure and speed were reduced to 10 bar and 100 m/s, respectively, causing additional damage to the sample without creating a hole. In the sixth test, the pressure was increased to 11 bar and the speed was 104 m/s. In this trial, the bullet penetrated the sample but it stopped within its thickness. The ballistic limit shows the minimum initial speed of the bullet needed to pass through the sample. In the case of an initial speed of 108 m/s, the velocity of the bullet after creating a hole in the sample was 35 m/s. The ballistic limit can be determined by calculating the velocity of entry and exit and the changes in the kinetic energy of the bullet. The change in kinetic energy can be calculated using Eq. (2):
2
Table 1. The result of ballistic test
Test No | Pressure (bar) | Velocity (m/s) | Result |
|---|---|---|---|
1 | 2 | 40 | No effect |
2 | 2.5 | 45 | No effect |
3 | 6 | 80 | Peeling gel coat layer |
4 | 12 | 108 | Milling and passing |
5 | 10 | 100 | Crushing and return |
6 | 11 | 104 | Stuck in the sample |
When the final velocity, Vf, is zero, the initial velocity, Vi, will equal the ballistic limit. By analyzing the test in which the bullet penetrated the plate, the ballistic limit was calculated to be 102.17 m/s. This value slightly deviates from the experimental result of 104 m/s. Figure 8 displays images from the experiments used to determine the ballistic limit.
Fig. 8 [Images not available. See PDF.]
The images of ballistic limit test: (a) test no. 3, (b) test no. 5, (c) test no. 4, (d) test no. 6
The Tensile Test
The tensile test was carried out on the G0, G3, and G5 samples, and the results of the testing are summarized in Table 2 and depicted in the force-strain diagram in Fig. 9.
Table 2. The obtained results of tensile test
Sample | E – modulus (GPa)) | F max (KN) | Ultimate strength (MPa) | Strain (%) |
|---|---|---|---|---|
G0 | 8.1 | 35.2 | 585.6 | 7.9 |
G3 | 7.4 | 30.4 | 555.9 | 7.2 |
G5 | 7.4 | 13.7 | 308.4 | 6.2 |
Fig. 9 [Images not available. See PDF.]
The force–strain diagram of the tensile test result
As seen in the image, the highest load required to fracture sample G0 was equal to 35.2 kN. By adding three holes to the sample, the force required to break it decreased by 13% to 30.4 kN, due to the stress concentration and the reduction of the cross-sectional area of the sample. With an increase in the number of holes, the maximum braking force decreased further to 13.7 kN. Moreover, the sudden decrease in forces observed at the end of the tests indicates that the rupture of all samples occurred abruptly, and the propagation of cracks between the holes did not take a significant amount of time. This observation suggests that there is an adequate adhesion between the polymeric base material and the glass fibers, established during the production of composite plates. A comparison between the G0 and G3 graphs reveals a slight reduction in the ultimate tensile strength and strain when the holes are arranged in a row. By analyzing the broken samples and their fracture cross sections, depicted in Fig. 10, the growth of the crack and the fracture path were identified. In the G0 sample the crack formed and broke almost flat across the sample, indicating a brittle fracture caused by normal stress. The crack growth and failure of the sample took place in the direction of least resistance and the direction of the holes, and this same process occurred in the G5 sample, resulting in failure at the lowest cross-sectional area and width of the sample.
Fig. 10 [Images not available. See PDF.]
The fracture cross-section of the tensile test samples: (a) G0, (b) G3, and (c) G5
The obtained results can be verified by viewing the cross-sectional images of the samples in Fig. 10. Controlling and examining the cross-section of the samples during the tensile test demonstrated that the fracture initiated from the inner surface of the holes, which suggests that the fibers were ruptured due to the drilling operation. Based on the observation of a 45° angle in the fracture cross-section of the G3 and G5 samples, it can be concluded that the failure occurred due to shear stress. The rupture of G0 samples occurred perpendicular to the direction of maximum tensile strength, indicating that the produced composite exhibits brittle behavior. Evidence of twitching and fibers protruding at the fracture cross section of the G0 sample suggests that the polymeric base material fractured initially. The favorable distribution and continuity of fibers within the polymeric base material resulted in effective energy absorption on the surface of the composite. In the case of the G5 sample, the rupture propagated from the middle hole and extended towards the side holes, continuing perpendicular to the tensile direction, similar to the behavior observed in the G0 sample. By examining the fracture patterns of the samples, it can be inferred that the rupture crack propagated through the middle hole, where the presence of the drilling hole resulted in a discontinuity in the sample.
The Bending Test
The results of the bending test on the samples, which was conducted to determine the maximum bending load, are presented in Table 3 and Fig. 11.
Table 3. The obtained result of the bending Test
Sample | F (kN) | Strain (%) |
|---|---|---|
G0 | 2.27 | 5.9 |
G3 | 1.47 | 4.2 |
G5 | 1.09 | 3.7 |
Fig. 11 [Images not available. See PDF.]
The force–strain of the bending test result
The G0 sample had the highest load to fracture at 2.27 kN. However, when three holes were drilled into the sample, the fracture load decreased by 35% to 1.47 kN as a result of increased tension and reduced cross-section. Drilling more holes led to an additional decrease in the fracture load to 1.09 kN. Another significant finding concerning the bending force and strain is that all samples exhibited similar force responses until reaching 2.2% strain, after which the separation between layers initiates. In all graphs, following the attainment of the peak point, fluctuations arise due to the fracture of composite layers, commencing from the outer surface. A comparative analysis of the tensile and bending tests leads to the conclusion that having holes arranged in a row results in a more pronounced reduction in the bending force compared to the tensile force. The presence of cracks and the direction of fracture were determined by examination of the fractured samples and their cross-sections, as illustrated in Fig. 12. In sample G0, the crack and fracture were nearly straight and along the width of the sample. The crack growth and failure were in the direction of least resistance. The same was observed in the G5 sample, where the failure occurred at the lowest cross-sectional area and width. The similar slope of the force-strain curves for all three samples indicates that they exhibit similar elastic behavior. In all three samples, the first failure was noticed in the outer layers under tensile stress, and in the perforated samples, the failure started from the inner surface of the holes. By focusing on the fracture of samples, it can be concluded that the rapture crack has passed from middle hole, in the point that the drilling hole led to discontinuity of the sample.
Fig. 12 [Images not available. See PDF.]
The fracture cross section of the samples after the bending test: (a) G0, (b) G3, and (c) G5
The Impact Test
The impact test was performed to determine the energy absorption during fracture in the samples. The results are displayed in Fig. 13 as a graph of energy absorption versus deflection. The figure shows that the maximum load applied to the material against the target occurred in all three samples at a deflection of 8 mm, which indicates a similar deformation behavior among the samples but varying maximum force values. The sample G0 had the highest absorbed force at 3.51 kN. However, after drilling three holes, the fracture force decreased to 2.98 kN, representing a reduction of 15% due to the increased tension concentration and reduced cross-section. The increase in number of holes led to an increase in brittleness, as demonstrated by the decreasing strain in the impact test, from 20 mm in G0 to 15 mm in G3. The results can be further analyzed by examining the images of the samples in Fig. 14. As depicted in Fig. 14, the applied force at the middle hole of G3 and G5 samples resulted in damage to the surrounding circumference of other holes. This observation highlights the effective adhesion between fibers and the polymeric base material, which facilitated the absorption of impact energy on the surface of the samples.
Fig. 13 [Images not available. See PDF.]
The force–displacement diagram of the impact test
Fig. 14 [Images not available. See PDF.]
The image after the impact test of samples: (a) G0, (b) G3, and (c) G5
Conclusions
The motivation to achieve high strength-to-weight ratios and cost-effectiveness drives the preference for polymer-based composites reinforced with glass fibers in scientific and industrial research. This study aimed to produce high-quality composite samples with minimal porosity defects and lamination using the RTM method. Specifically, the focus was on manufacturing 5-layer glass fiber-reinforced composites. Additionally, the impact of hole drilling on the samples was investigated. The results indicated that the presence of three holes arranged in a row had a lesser effect on reducing the ultimate tensile force compared to five holes. Furthermore, based on the bending test results, sample failure occurred on the side under tension, resulting in higher bending forces compared to tensile forces. The overall conclusions drawn from the present study can be summarized as follows:
The ballistic limit test results indicated that the produced polymer sheet exhibits a ballistic limit pressure of 11 bar and a velocity of 104 m/s. Beyond this threshold, the bullet was unable to penetrate the sheet and became immobilized.
The tensile test results showed that the G0 sample exhibited the highest fracture force, measuring 35.4 kN, while the G3 and G5 samples displayed fracture forces of 30.4 kN and 13.7 kN, respectively.
The G0 sample demonstrated the highest bending force of 2.27 kN, while the G3 and G5 samples displayed bending forces of 1.47 kN and 1.09 kN, respectively.
The impact resistance of the G5 sample was the lowest, measuring 2.79 kN.
Author contributions
Seyed Jalal Hashemi , Ali Sadooghi, Kaveh Rahmani wrote the main manuscript aslo did all the tests. Jafar Babazadeh produced samples and Alireza Nouri prepared figures and all the authors analysed the data and reviewed the manuscript.
Data availability
The raw/processed data required to reproduce these findings cannot be shared at this time as the data also forms part of an ongoing study. These authors are currently working on the effect of other parameters on the forming process.
Declarations
Competing interests
The authors declare no competing interests.
Conflict of interest
The authors declare that they have no conflict of interest.
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
References
1. Roohi, AH; Mirsadeghi, A; Sadooghi, A. MRX; 2022; 6,
2. Rahmani, K; Sadooghi, A; Hashemi, SJ. MRX; 2020; 8,
3. Hashemi, SJ; Sadooghi, A; Rahmani, K; Davarzani, F; Akbari, S. Mater Today Commun; 2020; 25, [DOI: https://dx.doi.org/10.1016/j.mtcomm.2020.101273]
4. Babazadeh, J; Rahmani, K; Hashemi, SJ; Sadooghi, A. MRX; 2021; 4,
5. Wu, Y; Shen, F; Zhang, M; Miao, Y; Wan, T; Xu, D. IEEE Trans Geosci Remote Sens; 2022; 60, 13.
6. Moumen, AE; Saouab, A; Imad, A; Kanit, T. J Adv Manuf Technol; 2023; 1, 20.
7. Sathishkumar, TP; Satheeshkumar, S; Naveen, J. J Reinf Plast Compos; 2014; 13, 1258. [DOI: https://dx.doi.org/10.1177/0731684414530790]
8. Cunningham, D; Harries, KA; Bell, AJ. J Eng Struct; 2015; 95, 815. [DOI: https://dx.doi.org/10.1016/j.engstruct.2015.03.042]
9. El-Sisi, AEDA; El-Emam, HM; Salim, HA; Sallam, HEDM. J Eng Struct; 2020; 215, 169. [DOI: https://dx.doi.org/10.1016/j.engstruct.2020.110690]
10. Kang, H; He, P; Zhang, C; Dai, Y; Shan, Z; Zang, Y; Lv, H. J Reinf Plast Compos; 2020; 39, 1718.
11. Supar, K. and Ahmad, H., 2017. IOP Conf. Ser.: Mater. Sci. Eng.271 1
12. Mortazavian, S; Fatemi, A. Compos B Eng; 2015; 72, 116. [DOI: https://dx.doi.org/10.1016/j.compositesb.2014.11.041]
13. Cordin, M; Bechtold, T; Pham, T. Cellul Chem; 2018; 25, 7197. [DOI: https://dx.doi.org/10.1007/s10570-018-2079-6]
14. Sikarwar, VS; Zhao, M; Clough, P; Yao, J; Zhong, X; Memon, MZ et al. Energy Environ Sci; 2016; 10, 2939. [DOI: https://dx.doi.org/10.1039/C6EE00935B]
15. Tamboura, S; Laribi, MA; Fitoussi, J; Shirinbayan, M; Tcharkhtchi, A; Dali, HB. Int J Fatigue; 2020; 138, [DOI: https://dx.doi.org/10.1016/j.ijfatigue.2020.105676]
16. Jiang, H; Ren, Y; Jin, Q; Zhu, G; Liu, Z. IJMS; 2020; 168,
17. Sebaey, TA; Rajak, DK; Mehboob, H. Compos Struct; 2021; 255, [DOI: https://dx.doi.org/10.1016/j.compstruct.2020.112910]
18. Francioso, V; Moro, C; Castillo, A; Velay-Lizancos, M. Constr Build Mater; 2021; 269, [DOI: https://dx.doi.org/10.1016/j.conbuildmat.2020.121243]
19. Rahimizadeh, A; Kalman, J; Fayazbakhsh, K; Lessard, L. Compos B Eng; 2019; 175, [DOI: https://dx.doi.org/10.1016/j.compositesb.2019.107101]
20. Ebadzadsahraei, S; Hassan Vakili, M. J Pipeline Syst Eng Pract; 2019; 3, 06019001. [DOI: https://dx.doi.org/10.1061/(ASCE)PS.1949-1204.0000387]
21. Liang, Z; Tang, B; Gui, Y; Zhao, Q. Mater Today Commun; 2020; 24, [DOI: https://dx.doi.org/10.1016/j.mtcomm.2020.101055]
22. Sun, X; Gao, C; Wang, H. Constr Build Mater; 2021; 269, [DOI: https://dx.doi.org/10.1016/j.conbuildmat.2020.121325]
23. Caminero, MA; Lopez-Pedrosa, M; Pinna, C; Soutis, C. Compos B: Eng; 2013; 53, 769. [DOI: https://dx.doi.org/10.1016/j.compositesb.2013.04.050]
24. Ridha, M; Wang, CH; Chen, BY; Tay, TE. Compos. Part A. Appl Sci; 2014; 58, 162.
25. Rahmani, K; Wheatley, G; Sadooghi, A; Hashemi, SJ; Babazadeh, J. MRX; 2021; 6,
26. Shih, CH; You, JL; Lee, YL; Cheng, AY; Chang, CP; Liu, YM et al. Polymers; 2022; 22, 5026. [DOI: https://dx.doi.org/10.3390/polym14225026]
27. Schaeffer, SL; Johnson, RL; Lewis, WB. J Test Eval; 1998; 26, 151. [DOI: https://dx.doi.org/10.1520/JTE11986J]
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Abstract
The high fracture strength and exceptional impact resistance of polymer-based composites are of paramount importance to various industries like aerospace, automotive, and construction. The resin transfer molding (RTM) process is used to produce composite samples of superior quality, minimal porosity, and reduced lamination defects. In the present study, the RTM method was employed to fabricate glass fiber-reinforced composites, aiming to investigate their specific mechanical properties and structural performance. The study initially determined the ballistic limit of the produced samples. Subsequently, experimental investigations were carried out to examine the impact of hole drilling on the tensile strength, flexural strength, and impact resistance of the samples. The results revealed that the produced polymer plate demonstrated a ballistic limit with a pressure of 11 bar and a speed of 104 m/s, leading to ball restriction in the plate. The sample without holes showed the highest fracture force, while samples with three and five holes exhibited reduced fracture forces. Additionally, bending force and impact resistance were lower in samples with multiple holes compared to the sample without holes. The impact resistance of the sample with five holes was the lowest among all configurations. The study revealed that the presence of three holes arranged in a row has a lesser impact on reducing the ultimate tensile force compared to the effect of five holes. Moreover, the bending test results indicated that sample failure occurred on the side under tension, resulting in higher bending forces than tensile forces.
Article highlights
Using resin transfer molding (RTM) method to produce high quality polymeric composite samples.
Determination of ballistic limit of glass fiber-reinforced composite samples.
Evaluation of the influence of the hole drilling on the tensile strength, flexural strength, and impact resistance of the samples.
Analysis of bonding and microstructural of the samples by SEM and EDX tests.
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1 Technical and Vocational University (TVU), Department of Mechanical Engineering, Tehran, Iran (GRID:grid.510424.6) (ISNI:0000 0004 7662 387X)
2 Shahid Rajaee Training Teacher University, Department of Mechanical Engineering, Tehran, Iran (GRID:grid.440791.f) (ISNI:0000 0004 0385 049X)
3 Bu-Ali Sina University, Mechanical Engineering Department, Hamedan, Iran (GRID:grid.411807.b) (ISNI:0000 0000 9828 9578); Basa Pars Sanat Knowledge Enterprise Company, R&D Center, Takestan, Iran (GRID:grid.411807.b)
4 Qom University of Technology, Department of Mechanical Engineering, Qom, Iran (GRID:grid.459900.1) (ISNI:0000 0004 4914 3344)
5 Amirkabir University of Technology (Tehran Polytechnic), Biomedical Engineering Department, Tehran, Iran (GRID:grid.411368.9) (ISNI:0000 0004 0611 6995)