Experimental Analysis on the Bulk and Interlaminar Fatigue Properties of Carbon Fiber/Epoxy Composites with Matrix Reinforced by Carbon Nanotubes and Graphene Nanoplatelets(III)

View Statistics Email Alert RSS Feed

Information

Details

Project title

Code/計畫編號

MOST107-2221-E019-024-MY3

Translated Name/計畫中文名

同時添加碳奈米管及石墨烯微片於基材對碳纖維/環氧樹脂複合材料整體及層間疲勞性質影響之實驗與分析(III)

Project Coordinator/計畫主持人

Yi-Ming Jen

Funding Organization/主管機關

National Science and Technology Council

Department/Unit

Department of Mechanical and Mechatronic Engineering

Website

https://www.grb.gov.tw/search/planDetail?id=13325977

Year

2020

Start date/計畫起

01-08-2020

Expected Completion/計畫迄

31-07-2021

Bugetid/研究經費

805千元

ResearchField/研究領域

機械工程

由於高比強度及高比勁度的特性，纖維強化高分子複合材料已被各個產業廣泛地應用。然而，在承受週次或動態的外加負荷時，疲勞破壞是纖維強化高分子複合材料常見的破壞模式之一；脫層的形成及成長則是疲勞破壞過程中的關鍵步驟。如果能抑制脫層的形成及成長，將能有效延長纖維複合材料的使用壽命。由於脫層現象與基材的性質及纖維/基材間的黏著強度有關，因此近年來已有研究開始嘗試在高分子基材中添加奈米填料，以期強化纖維複合材料的層間特性，進而達到增進整體複合材料強度的目的。但在這些研究中，大多僅針對添加單一種奈米填料對纖維複合材料在承受靜態負荷下的整體或層間機械性質進行研究；層間行為的討論也僅考量單一負荷模式下的性質。對於添加兩種奈米填料的協同效應、承受週次負荷的漸進式退化及層間複雜的負荷模式等變因對纖維複合材料整體及層間機械性質影響的探討相當少見。因此，本計畫將利用三年的時間，以實驗的方法針對在基材中添加碳奈米管及石墨烯微片的碳纖維/環氧樹脂奈米複合材料進行整體及層間的靜態/疲勞特性研究。在試片的製作上，將考量五種不同的奈米填料總添加量及七種不同的兩填料間配置比例。另外，計畫中將應用行星式攪拌及超音波均質技術使奈米填料均勻分散於基材脂中。計畫第一年將針對此奈米複合材料整體的拉伸及撓曲靜態/疲勞性質進測試，以求得相關的靜態拉伸/撓曲機械性質及拉伸/撓曲疲勞曲線。第二年將利用雙懸臂樑法及末端缺口撓曲法，分別針對含有脫層之奈米複合材料試片進行mode I 及mode II層間性質的分析。第三年將利用混合模式彎矩法，在五種選定的混合mode I 及mode II 模式比下，針對含有脫層之奈米複合材料試片在混合負荷模式下的層間性質進行研究。計畫第二年及第三年中以實驗探討的層間性質包括層間破裂韌性、脫層形成壽命及脫層成長速率。計畫的目的在探討有無添加奈米填料、添加奈米填料的種類、添加碳奈米填料總含量及兩種奈米填料的含量比例等四項變因對此奈米複合材料整體及層間靜態/疲勞性質的影響。各項測試結束後，將藉由斷面的觀察來推斷奈米填料強化複合材料整體及層間機械性質的機制。另外，對於此類奈米複合材料的層間疲勞行為，本研究將以數學模型來描述週次負荷下，最大應變能釋放率與脫層起始壽命間的關係；以及脫層成長速率與最大應變能釋放率間的關係。"Due to the characteristics of high specific strength and high specific stiffness, fiber reinforced polymer composites have been widely applied in various industries. However, the fatigue damage is the most common failure mode when these composites are subjected to the cyclic loading or dynamic loading. Moreover, delamination formation and growth are the critical procedures during the progressive development of fatigue failure. The durability of fiber-reinforced composite materials will be improved significantly provided that the initiation and propagation of delamination are inhibited effectively. Delamination phenomenon strongly depends on the properties of the matrix and fiber/matrix adhesions. Accordingly, recent studies attempt to improve the interlaminar properties by dispersing nanofillers in the polymer matrix on the purpose of increasing the strength of fiber-reinforced composites. However, in most past studies, only single type of nanofiller was employed to improve the bulk or interlaminar static properties of fiber-reinforced composites. Furthermore, most of these related studies investigated the interlaminar fracture properties under single loading mode. The topics such as the synergetic effect of adding two types of nanofillers, the progressive degradation of properties due to cyclic loading and the complexity of the interlaminar loading modes were rarely studied before. Therefore, the three-year project will experimentally investigate the static and fatigue properties of the bulk and the interlaminar static/fatigue properties of the carbon fiber/epoxy composites with the matrix enhanced by adding the carbon nanotubes and graphene nanoplatelets. In the preparation of specimens, five total amounts of the two employed fillers and the seven allocation ratios between two fillers will be considered. In addition, the techniques of planetary mixture and ultrasonic homogenization will be applied in the project to obtain the uniform dispersion of nanofillers in the matrix. In the first year of the project, the tensile and flexural static/cyclic tests of carbon fiber/epoxy nanocomposites will be performed to obtain the tensile/flexural monotonic properties and tensile/flexural fatigue curves. The double cantilever beam (DCB) method and the end-notched flexure (ENF) method will be applied in the next year to experimentally analyze the mode I and mode II interlaminar properties of the precracked nanocomposites, respectively. In the third year, under five different mixed-mode conditions, the interlaminar properties of the precracked nanocomposites will be studied using the mixed-mode bending (MMB) method. The interlaminar properties explored in the second and third years include the fracture toughness, the delamination onset life, and the delamination growth rate. The purpose of this project is to study the influences of whether the nanofiller is applied, the number of types of nanofillers employed, the total amount of two nanofillers, and the allocation ratio of two nanofillers on the bulk and interlaminar monotonic/fatigue properties of the carbon fiber/epoxy composites. The fracture surfaces obtained after all the tests will be examined to verify the improvement mechanism of nanofillers on the bulk/interlaminar properties. Furthermore, the mathematical models will be developed to describe the relationships between the maximum strain energy release rate and the delamination onset life; and between the delamination growth rate and the maximum strain energy release rate, respectively."

Keyword(s)

疲勞
層間性質
碳纖維/環氧樹脂複合材料
碳奈米管
石墨烯微片
雙懸臂樑法
末端缺口撓曲法
混合模式彎矩法
混合模式比
破裂韌性
脫層起始壽命
脫層成長速率
fatigue
interlaminar property
carbon fiber/epoxy composite
carbon nanotube (CNT)
graphene nanoplatelets (GNP)
double cantilever beam (DCB) method
end notched flexure (ENF) method
mixed-mode bending (MMB) method
mixed-mode ratio
fracture toughness
delamination onset life
delamination growth rate

DSpace CRIS

Experimental Analysis on the Bulk and Interlaminar Fatigue Properties of Carbon Fiber/Epoxy Composites with Matrix Reinforced by Carbon Nanotubes and Graphene Nanoplatelets(III)

Details

Description