scholarly journals Analysis of Impact Characteristics and Detection of Internal Defects for Unidirectional Carbon Composites with Respect to Fiber Orientation

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 203
Author(s):  
Sun-ho Go ◽  
Alexandre Tugirumubano ◽  
Hong-gun Kim
Keyword(s):  
Carbon Fiber ◽  
Impact Test ◽  
Carbon Fiber Composites ◽  
Internal Defects ◽  
Impact Tests ◽  
Drop Weight ◽  
Weight Impact ◽  
Fibers Orientation ◽  
Lock In ◽  
The Impact

With the increasing use of carbon fiber reinforced plastics in various fields, carbon fiber composites based on prepregs have attracted attention in industries and academia research. However, prepreg manufacturing processes are costly, and the strength of structures varies depending on the orientation and defects (pores and delamination). For the non-contact evaluation of internal defects, the lock-in infrared thermography was proposed to investigate the defects in the composites subjected to the compression after impact test (CAI). The drop-weight impact test was conducted to study the impact behavior of the composites according to fibers orientation for composite fabricated using unidirectional (UD) carbon fiber prepregs. Using CAI tests, the residual compressive strengths were determined, and the damage modes were detected using a thermal camera. The results of the drop weight impact tests showed that the specimen laminated at 0° suffered the largest damage because of susceptibility of the resin to impact. The specimens with 0°/90° and +45°/−45° fibers orientation exhibited more than 90% of the impact energy absorption and good impact resistance. Furthermore, the specimens that underwent the impact tests were subjected to compressive test simultaneously with the lock-in thermography defects detection. The results showed that internal delamination, fibers splitting, and broken fibers occurred. The temperature differences in the residual compression tests were not significant.

scholarly journals Analysis of Impact Characteristics and Detection of Internal Defects for Unidirectional Carbon Composites with Respect to Fiber Orientation

2020 ◽  
Author(s):  
Sun-ho Go ◽  
Alexandre Tugirumubano ◽  
and Hong-gun Kim
Keyword(s):  
Carbon Fiber ◽  
Carbon Fiber Composites ◽  
Compression Tests ◽  
Internal Defects ◽  
Finite Elements Analysis ◽  
Impact Tests ◽  
Drop Weight ◽  
Weight Impact ◽  
Lock In ◽  
The Impact

.With the increasing use of carbon fiber reinforced plastics in various area, carbon fiber composites based on prepregs have attracted attention in industries and academia research. However, prepreg manufacturing processes are costly, and the strength of structures varies depending on the orientation and defects (pores and delamination). For non-contact evaluation of internal defects, we proposed lock-in infrared thermography to investigate orientation angles after a compression test. We also conducted a drop-weight impact test to study the behaviour of the composites after impact according the fibers orientation for composite fabricated using unidirectional carbon fiber prepregs. Using CAI tests, we determined the residual compressive strength and confirmed the damage modes using a thermal camera. The results of the drop weight impact tests show that the specimen laminated at 0° suffered the largest damage because of susceptibility of the resin to impact. In contrast, the specimens oriented in of 0°/90° and +45°/–45° directions transferred more than 90% of the impact energy back to the impactor because of the lamination of fibers in the orthogonal directions. Furthermore, the specimens that underwent complete damage in the impact tests were subjected to the lock-in method and showed internal delamination and cut fibers. With the finite elements analysis, the damage of each ply could be observed. Moreover, the temperature differences in the residual compression tests were not significant.

Recovery of impact-damaged carbon fiber–reinforced composites using induction heating

2021 ◽  
pp. 002199832110587
Author(s):  
Sultan M Bayazeid ◽  
Kim-Leng Poon ◽  
Balakrishnan Subeshan ◽  
Mohammed Alamir ◽  
Eylem Asmatulu
Keyword(s):  
Tensile Strength ◽  
Carbon Fiber ◽  
Impact Test ◽  
Impact Damage ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Drop Weight ◽  
Carbon Fiber Reinforced Composites ◽  
Weight Impact ◽  
The Impact

Carbon fiber–reinforced composites (CFRCs) have been used extensively in structural applications within the aerospace and automotive manufacturing industries. However, several other applications have been recognized. These take advantage of the additional properties of CFRCs, which lead to providing better performance for structures. However, in their service environment, these CFRCs are inevitably susceptible to impact damage from multiple sources, and they must be able to recover from impacts to meet structural requirements. This study directs an experimental investigation of using induction heating (IH) for an impact-damaged CFRC. Here, IH process parameters, including the effects of electromagnetic frequency and generator power on the recovery of impact-damaged CFRC, have been analyzed. The anisotropic conductivity characteristics and the relationship between the drop-weight impact depth and conductivity of CFRC garnered much attention. This paper also offers the electromagnetic properties of CFRC for various applications. In this study, CFRC cured samples were obtained from Cetex® TC1200 PEEK, AS4 145 gsm, 16 unidirectional plies. Three variants of CFRC samples were tested: undamaged samples; samples with impact damage introduced in the center by a drop-weight impact test, according to the ASTM D7136/7136M standard; and samples with drop-weight impact damage recovered using the IH system. This work presents the results of the tensile strength of CFRC samples to assess the comparison of undamaged samples, samples damaged after the drop-weight impact test, and samples recovered after the drop-weight impact test. IH is appropriate for the recovery of impact-damaged CFRC samples, aiding in the conversion of electromagnetic energy to heat in order to generate mechanisms on components to recover the impact-damaged CFRC samples. Experimental results show that the impact-damaged area of the recovered CFRC samples is 37.0% less than that of damaged CFRC samples, and tensile strength results also improved after the impact-damaged CFRC samples were recovered. These results show that the IH method can effectively improve the impact damage performance of CFRC. The outcome of this study is promising for use in many applications, especially in the aerospace and automotive industries.

The effect of microwave pretreatment on impact crushing of lead-zinc ore

2021 ◽  
Vol 118 (5) ◽  
pp. 501
Author(s):  
Yulong Liu ◽  
Dexin Ding ◽  
Wenguang Chen ◽  
Nan Hu ◽  
Lingling Wu ◽  
...  
Keyword(s):  
Energy Input ◽  
Impact Test ◽  
Characteristic Parameters ◽  
Microwave Pretreatment ◽  
Drop Weight ◽  
Lead Zinc ◽  
Weight Impact ◽  
Impact Crushing ◽  
The Impact ◽  
The Relationship

The relationship between energy input and particle size of ore samples after crushing and effect of microwave pretreatment on impact crushing of lead-zinc ore were studied by drop weight impact test. The results showed that the lead-zinc ore became softer and had higher degree of crushing after microwave pretreatment. Compared with continuous microwave pretreatment, pulsed microwave pretreatment could improve the drop weight impact crushing efficiency of lead-zinc ore. When the specific comminution energy were 5 kW h/t, 10 kW h/t respectively, the crushing characteristic parameters t10 were 60.42% and 67.46% respectively by continuous microwave. But the values of t10 were increased to 68.64% and 75.88% respectively after pulsed microwave radiation under same microwave power and time. In addition, water quenching could more promote the impact crushing efficiency of lead-zinc ore after microwave irradiation.

scholarly journals Experimental Investigation on the Impact Resistance of Carbon Fibers Reinforced Coral Concrete

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4000 ◽  
Author(s):  
Bing Liu ◽  
Jingkai Zhou ◽  
Xiaoyan Wen ◽  
Jianhua Guo ◽  
Xuanyu Zhang ◽  
...  
Keyword(s):  
Weibull Distribution ◽  
Carbon Fibers ◽  
Impact Test ◽  
Concrete Strength ◽  
Impact Resistance ◽  
Initial Crack ◽  
Drop Weight ◽  
Weight Impact ◽  
The Impact ◽  
Two Parameter

In this study, the impact resistance of coral concrete with different carbon fiber (CF) dosages subjected to drop-weight impact test was investigated. For this purpose, three concrete strength grades (C20, C30, C40) and six CF dosages (0.0%, 0.3%, 0.6%, 1.0%, 1.5%, and 2.0% by weight of the binder) were considered, and a total of 18 groups of carbon fibers reinforced coral concrete (CFRCC) were cast. For each group, eight specimens were tested following the drop-weight impact test suggested by CECS 13. Then, the two-parameter Weibull distribution theory was adopted to statistically analyze the variations in experimental results. The results indicated that the addition of CFs could transform the failure pattern from obvious brittleness to relatively good ductility and improve the impact resistance of coral concrete. Moreover, the impact resistance of CFRCC increases with the CF dosage increasing. The statistical analysis showed that the probability distribution of the blow numbers at the initial crack and final failure of CFRCC approximately follows the two-parameter Weibull distribution.

Dynamic Response of 3D-Printed Bi-Material Structure Using Drop Weight Impact Test

2017 ◽  
Author(s):  
Anish Ravindra Amin ◽  
Yi-Tang Kao ◽  
Bruce L. Tai ◽  
Jyhwen Wang
Keyword(s):  
Energy Absorption ◽  
Impact Test ◽  
Impact Resistance ◽  
Silicone Elastomer ◽  
Material Structure ◽  
Pu Foam ◽  
Drop Weight ◽  
3D Printed ◽  
Weight Impact ◽  
The Impact

Additive manufacturing has led to increasing number of applications that require complex geometries and multiple materials. This paper presented a bi-material structure (BMS) composed of a cushion matrix held by a 3D printed frame structure for an improved impact resistance. The study mainly focused on understanding the effects of structural topology and matrix material. Two matrix materials, silicone elastomer and polyurethane (PU) foam, were selected to impregnate into two different PLA frame structures. Drop weight impact test was carried out to measure the impact force and energy absorption. The results showed that the overall impact resistance was dominated by the frame, while the matrix reinforcement required proper structural interlocking mechanism and material matching. In the particular specimens of this study, PU foam led to more energy absorption and force bearing capacity of the structure than the silicone elastomer.

scholarly journals Thermoelastic Investigation of Carbon-Fiber-Reinforced Composites Using a Drop-Weight Impact Test

2020 ◽  
Vol 11 (1) ◽  
pp. 207
Author(s):  
Zahra Andleeb ◽  
Sohail Malik ◽  
Hassan Abbas Khawaja ◽  
Anders Samuelsen Nordli ◽  
Ståle Antonsen ◽  
...  
Keyword(s):  
Composite Materials ◽  
Carbon Fiber ◽  
Infrared Thermography ◽  
Impact Test ◽  
Heat Diffusion ◽  
Fiber Reinforced Polymers ◽  
Fiber Reinforced ◽  
Drop Weight ◽  
Weight Impact ◽  
Carbon Fiber Reinforced

Composite materials are becoming more popular in technological applications due to the significant weight savings and strength offered by these materials compared to metallic materials. In many of these practical situations, the structures suffer from drop-impact loads. Materials and structures significantly change their behavior when submitted to impact loading conditions compared to quasi-static loading. The present work is devoted to investigating the thermal process in carbon-fiber-reinforced polymers (CFRP) subjected to a drop test. A novel drop-weight impact test experiment is performed to evaluate parameters specific to 3D composite materials. A strain gauge rosette and infrared thermography are employed to record the kinematic and thermal fields on the composites’ surfaces. This technique is nondestructive and offers an extensive full-field investigation of a material’s response. The combination of strain and infrared thermography data allows a comprehensive analysis of thermoelastic effects in CFRP when subjected to impacts. The experimental results are validated using numerical analysis by developing a MATLAB® code to analyze whether the coupled heat and wave equation phenomenon exists in a two-dimensional polar coordinate system by discretizing through a forward-time central-space (FTCS) finite-difference method (FDM). The results show the coupling has no significant impact as the waves generated due to impact disappears in 0.015 s. In contrast, heat diffusion happens for over a one-second period. This study demonstrates that the heat equation alone governs the CFRP heat flow process, and the thermoelastic effect is negligible for the specific drop-weight impact load.

Repeated Drop-Weight Impact Tests on RPC Containing Hybrid Fibers

2020 ◽  
Vol 897 ◽  
pp. 49-55 ◽  
Author(s):  
Hussain A. Jabir ◽  
Sallal R. Abid ◽  
Munther L. Abdul Hussein ◽  
Sajjad H. Ali
Keyword(s):  
Steel Fiber ◽  
Impact Resistance ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Hybrid Fibers ◽  
Impact Tests ◽  
Drop Weight ◽  
Weight Impact ◽  
Reactive Powder ◽  
The Impact

The impact resistance of micro-steel fiber-reinforced and hybrid fiber-reinforced reactive powder concrete is investigated in this study. Six groups of specimens were prepared with 2.5% volumetric contents of different combinations of fibers. For this purpose, micro-steel fibers with 6 and 15 mm length in addition to polypropylene fibers were used. Each group includes 12 identical specimens. The impact tests were conducted using the repeated drop-weight impact test of ACI 544-2R. However, higher drop-height (700 mm) and drop-weight (10 kg) were adopted to accelerate the failure and reduce the effort required to crack the specimens. The test results showed that the use of only 15 mm micro-steel fiber led to much higher impact resistance than other micro-steel fiber combinations. The recorded number of blows for the group with SF15 was 247, while those of SF6 and combined SF6 and SF15 were 127 and 112, respectively. The replacement of 0.5% of micro-steel fiber by 0.5% of PP fiber was found to reduce the impact resistance regardless of the type or combination of the used micro-steel fiber.

scholarly journals The impact fracture behaviors of CFRP/EVA composites by drop-weight impact test

2017 ◽  
Vol 21 ◽  
pp. 23-32 ◽  
Author(s):  
Sun-Ho Go ◽  
Hong-Gun Kim ◽  
Hee-Jae Shin ◽  
Min-Sang Lee ◽  
Hyun-Gyung Yoon ◽  
...  
Keyword(s):  
Impact Test ◽  
Impact Fracture ◽  
Drop Weight ◽  
Fracture Behaviors ◽  
Weight Impact ◽  
The Impact
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