Experimental Statistical Analysis of Tensile and Shear Properties of the Jute Fabric Epoxy Composites

ABSTRACT

The main objective of this study was to determine the mechanical properties and their analysis using uncertainty analysis of biodegradable Jute fabric composite. Jute fabric composite samples were fabricated using Vacuum infusion method (VIM) and mechanical tests such as tensile and shear tests were performed. Fiber volume fraction of 38% was achieved after fabrication and samples for tensile and shear tests were cut as per ASTM standards. A novel approach for making the notch on the shear samples was developed using the Vertical grinding machine (VGM) where better control over the notch dimensions was achieved. The use of Abrasive water jet machining (AWJM) for cutting of samples was preferred over conventional Hand Grinder (HG) due to higher accuracy on the dimensions and better stress results. The samples which were cut using AWJM showed the 52.3, 62.4, and 15.4% higher shear stress, modulus and strain, respectively, than those cut using HG. Both tensile and shear tests showed non-linear behavior and variability in the results which had little influence over the reliability of its mechanical properties. These characteristics were then confirmed through scanning electron microscope (SEM) images where fiber breakage, resin pockets, matrix cracking, and permeation of the matrix in the fabric were observed. The uncertainty analysis of these test results using different distribution parameters helped to understand the key parameters for product design using such material and optimize the factor of safety, which is an important consideration when using the composite material. The significance and reliability of such composites could help replace the E-glass fiber composite for aerospace and automotive applications.

摘要

本研究的主要目的是通过生物降解黄麻织物复合材料的不确定度分析来确定其力学性能及其分析。采用真空浸渍法 (VIM) 制备了黄麻织物复合材料样品, 并进行了拉伸和剪切等力学试验. 制造后, 纤维体积分数达到38%, 拉伸和剪切试验的样品按照ASTM标准切割. 使用立式磨床 (VGM) 开发了一种在剪切样品上制作切口的新方法, 该方法可以更好地控制切口尺寸. 由于尺寸精度更高和应力结果更好, 与传统的手动研磨机 (HG) 相比, 优先使用磨料水射流加工 (AWJM) 切割样品。使用AWJM切割的样品显示剪切应力、模量和应变分别比使用HG切割的样品高52.3%、62.4%和15.4%. 拉伸和剪切试验均显示出非线性行为和结果的可变性, 这对其机械性能的可靠性几乎没有影响. 然后通过扫描电子显微镜 (SEM) 图像确认这些特征, 其中观察到纤维断裂、树脂袋、基体开裂以及基体在织物中的渗透. 使用不同分布参数对这些试验结果进行的不确定性分析有助于了解使用此类材料进行产品设计的关键参数, 并优化安全系数, 这是使用复合材料时的一个重要考虑因素. 这种复合材料的重要性和可靠性有助于替代E-玻璃纤维复合材料用于航空航天和汽车应用.

KEYWORDS:

• Jute fiber composites
• mechanical property
• testing
• statistical analysis
• uncertainty modeling
• vacuum infusion method

关键词:

• 黄麻纤维复合材料
• 力学性能
• 测试
• 统计分析
• 不确定度建模
• 真空灌注法

Acknowledgments

The authors would like to thanks to Dr. Atul R. Bhagat, Head of the composite lab at DRDL Imarat, Hyderabad for their support in allowing us to perform the tests.

Highlights

• The tensile tested results of the jute fiber composites showed the mean value of the longitudinal modulus, longitudinal tensile strength, in-plane Poisson ratio and tensile strain are 11.38 GPa, 44.33 MPa, 0.011, and 0.0057, respectively.

• The shear test samples prepared by the water jet machining, the shear strength properties showed that the mean values of the in plane shear modulus, shear strength and shear strain failure are 1.85 GPa, 55.11MPa and 0.02, respectively.

• There is a possibility of the under estimation of the mean value of the shear stress, the shear modulus and the shear strain by 52.3, 62.4, and 15.4%, respectively, if the water jet machining was not considered for the determination of the mechanical properties in shear tests.

• The statistical properties for the tensile modulus and tensile strength were showed that the Weibull distributions for the jute fiber composites, respectively.

• The statistical properties for the shear modulus and shear strength properties showed that the lognormal distribution and Weibull distribution for the jute fiber composites, respectively.