Materials Selection of Thermoplastic Matrices of Natural Fibre Composites for Cyclist Helmet Using an Integration of DMAIC Approach in Six Sigma Method Together with Grey Relational Analysis Approach

Natural fibre reinforced polymer composite(NFRPC)materials are gaining popularity in the modern world due to their eco-friendliness,lightweight nature,life-cycle superiority,biodegradability,low cost,and noble mechanical properties.Due to the wide variety of materials available that have comparable attributes and satisfy the requirements of the product design specification,material selection has become a crucial component of design for engineers.This paper discusses the study’s findings in choosing the suitable thermoplastic matrices of Natural Fibre Composites for Cyclist Helmet utilising the DMAIC,and GRA approaches.The results are based on integrating two decision methods implemented utilising two distinct decision-making approaches:qualitative and quantitative.This study suggested thermoplastic polyethylene as a particularly ideal matrix in composite cyclist helmets during the selection process for the best thermoplastic matrices material using the 6σtechnique,with the decision based on the highest performance,the lightest weight,and the most environmentally friendly criteria.The DMAIC and GRA approach significantly influenced the material selection process by offering different tools for each phase.In the future study,selection technique may have been more exhaustive if more information from other factors had been added.

Material Selection of a Natural Fibre Reinforced Polymer Composites using an Analytical Approach

Material selection has become a critical part of design for engineers,due to availability of diverse choice of materials that have similar properties and meet the product design specification.Implementation of statistical analysis alone makes it difficult to identify the ideal composition of the final composite.An integrated approach between statistical model and micromechanical model is desired.In this paper,resultant natural fibre and polymer matrix from previous study is used to estimate the mechanical properties such as density,Young’s modulus and tensile strength.Four levels of fibre loading are used to compare the optimum natural fibre reinforced polymer composite(NFRPC).The result from this analytical approach revealed that kenaf/polystyrene(PS)with 40%fibre loading is the ideal composite in automotive component application.It was found that the ideal composite score is 1.156 g/cm^(3),24.2 GPa and 413.4 MPa for density,Young’s modulus and tensile strength,respectively.A suggestion to increase the properties on Young’s modulus are also presented.This work proves that the statistical model is well incorporated with the analytical approach to choose the correct composite to use in automotive application.

Analytical study of the interface in fibre-reinforced 2D composite material

Imperfect bonding between the constitutive components can greatly affect the properties of the composite structures.An asymptotic analysis of different types of imperfect interfaces arising in the problem of 2D fibrereinforced composite materials are proposed.The performed study is based on the asymptotic reduction of the governing biharmonic problem into two harmonic problems.All solutions are obtained in a closed analytical form.The obtained results can be used for the calculation of pull-out and pushout tests,as well as for the investigation of the fracture of composite materials.

Vertex angles effects in the energy absorption of axially crushed kenaf fibre-epoxy reinforced elliptical composite cones

Experimental quasi-static crushing tests were conducted by using a universal testing machine format kenaf-epoxy composite elliptical cones. The work focused on the vertex angle's effects on energy absorption capability; the vertex angles vary from 0° to 24° in 6 increments. The failure modes of the kenaf fibre epoxy composite elliptical cones were observed utilising delegate photos taken during the quasistatic crushing test. Load-deformation curves and deformation histories of typical specimens are presented and discussed. Moreover, the effects of cone vertex angles on the load carrying capacity and the energy absorption capability are also discussed. The results show that the energy absorption abilities significantly influence the ellipticity vertex angle as the load carrying capacity. We concluded that the quasi-static axial crushing behaviour of elliptical mat laminated composite cones is strongly affected by their structural geometry and the specific energy absorbed by the composite elliptical cones with vertex angles of 6°, 12°, 18°, and 24°, which is more than an elliptical cone with the vertex angle of 0°(the elliptical tube) at any given deformation. However, the specific energy absorption for the elliptical composite cone showed a positive correlation, i.e., the more the angle increased, the more energy was absorbed. In this regard, an elliptical composite cone with a 24° angle exhibited the best energy absorption capability.

ANISOTROPY OF THE KERATIN FIBRE COMPOSITE

This paper presents a composite model of the natural keratin fibres (wool and hair) whichconsists essentially of isotropic viscoelastic filaments, oriented parallel to each other in the fibreaxial direction, embedded in an isotropic viscoelastic matrix. The model accurately fits the exper-imental data on the fibre axial stress relaxation moduli and provides upper and lower bounds forthe initial/final values for the fibre transverse tensile and shear stress relaxation moduli andtransverse Poisson’s ratio. The partially water penertrable filament phase of the composite modelis identified as the microfibrils in the fine structure of keratin. The strong anisotropy of keratinsin mechanical properties and hygral/thermal expansion is analyzed in terms of composite struc-ture and mechanical as well as the thermal/hygral properties of the two constituent phases.

Concurrent Material Selection of Natural Fibre Filament for Fused Deposition Modeling Using Integration of Analytic Hierarchy Process/Analytic Network Process

The employment of natural fibres in fused deposition modeling has raised much attention from researchers in finding a suitable formulation for the natural fibre composite filaments.Moreover,selection of suitable natural fibres for fused deposition modeling should be performed before the development of the composites.It could not be performed without identifying selection criteria that comprehend both materials and fused deposition modeling process requirements.Therefore,in this study,integration of the Analytic Hierarchy Process(AHP)/Analytic Network Process(ANP)has been introduced in selecting the natural fibres based in different clusters of selection concurrently.The selection process has been performed based on the interdependency among the selection criteria.Pairwise comparison matrices are constructed based on AHP’s hierarchical model and super matrices are constructed based on the ANP’s network model.As a result,flax fibre has ranked at the top of the selection by scored 19.5%from the overall evaluation.Flax fibre has excellent material properties and been found in various natural fibre composite applications.Further investigation is needed to study the compatibility of this fibre to be reinforced with a thermoplastic polymer matrix to develop a resultant natural fibre composite filament for fused deposition modeling.

An engineering analysis of penetration of metal ball into fibre-reinforced composite targets

An engineering analysis of computing the penetration problem of a steel ball penetrating into fibre-reinforced composite targets is presented. Assume the metal ball is a rigid body, and the composite target is a transversely isotropic elasto-plastic material. In the analysis, a spherical cavity dilatation model is incorporated in the cylindrical cavity penetration method. Simulation results based on the modified model are in good agreement with the results for 3-D Kevlar woven （3DKW） composite anti-penetration experiments. Effects of the target material parameters and impact parameters on the penetration problem are also studied.

孔柱锥度对纤维柱增强夹芯结构压缩性能的影响

纤维柱增强泡沫夹芯材料孔柱在加工过程中会产生一定的锥度,为研究孔柱锥度对夹芯结构压缩性能的影响,设计并制备了15组不同锥度孔柱的纤维柱增强复合材料。对制备的夹芯结构进行准静态压缩试验并结合数值模拟,研究了孔柱锥度与芯材厚度对夹芯结构压缩强度、模量、比强度以及失效形式的影响。结果表明:芯材厚度为25 mm、30 mm、35 mm的夹芯结构,孔柱锥度由0°提升至16°后,压缩强度分别提升了14.7%、22%、24.8%,压缩模量分别提升了25.9%、31.6%、37.7%,比强度分别提升了4%、9.95%、10.24%;孔柱锥度较小和无锥度孔柱的夹芯结构失效形式为纤维柱的屈曲、断裂,且屈曲、断裂位置随着孔柱锥度的增大逐渐向孔径较小的一端偏移;当孔柱锥度提升至16°时,夹芯结构中部分纤维柱孔径较小的一端与面板发生脱黏,导致纤维柱未能起到良好的支撑效果,影响材料的力学性能。

MXene/石墨烯复合材料的研究进展

随着对MXene和石墨烯的研究,发现它们在电学、储能、力学和光学领域等方面都有重要的应用前景。本文综述了当前MXene/石墨烯复合材料的研究进展,重点介绍了MXene/石墨烯复合凝胶、薄膜、纤维的制备,从简单复合到通过引入其他组分来改善MXene和石墨烯所固有的缺点,解决了MXene的弱凝胶化问题、氧化石墨烯机械强度不足、低导电性等问题,从而提高了复合材料的性能,以便能够在实际使用过程中达到最佳性能。同时介绍了复合材料在传感器、可穿戴设备、电磁屏蔽、超级电容器、航空航天以及生物检测器中的应用及未来发展的可行性。最后,对MXene/石墨烯的复合材料未来发展提出展望。

玻璃纤维/环氧树脂/不锈钢网复合材料性能研究

为研究金属网厚度、金属网粒度、上层预浸料厚度和铺层角度对复合材料力学性能的影响。制备了1.8 mm厚度的9组玻璃纤维/环氧树脂/不锈钢网复合材料,对其进行正交试验仿真分析,并与试验结果对比。结果表明:仿真与试验的最大偏差为4.36%,证明仿真结果可靠。当金属网厚度为0.4 mm,粒度为590μm,上层预浸料厚度为0.9 mm,铺层角度为0°时力学性能最优。

煤矿机器人防爆外壳纤维复合增强材料研究与应用

针对传统金属材料制作井下机器人防爆外壳整体重量大、续航时间短、制造和使用成本高等问题,安徽玄离智能科技股份有限公司研发了纤维复合增强材料作为井下巡检机器人的防爆外壳。对可做煤矿机器人防爆外壳的纤维增强复合材料相关性能和安全性控制进行了深入研究;巡检机器人采用这种自主研发的轻量化复合增强材料后,机器人总重量只有220 kg,是采用传统金属材料制作同类产品重量的1/10,可以节省90%以上的设备制造成本,并可大幅降低能耗,从而增加了续航时间,进一步提升了产品性能。

钢制外浮顶用新型碳纤维复合材料涂层材料的设计与研究

针对钢制浮顶油罐外浮顶大面积暴露在大气中所产生的腐蚀现象,设计了一种新型碳纤维复合材料作为钢制外浮顶涂层材料,即利用滑石粉和KH550对常用树脂涂料(环氧乙烯基酯树脂、环氧树脂和间苯树脂)进行改性处理,并随后在其中掺入适量碳纤维粉合成出一系列新型碳纤维复合涂料。在与上述纯树脂涂料以及碳纤维粉复合未改性树脂涂料进行防腐性能比较时发现,改性处理后的环氧乙烯基酯树脂复合碳纤维粉涂料的防腐性能最佳,有望用于钢制外浮顶的防腐。

复合材料单向板偏轴拉伸试验方法的研究

通过复合材料单向板的偏轴拉伸试验可以获得材料在拉伸和剪切应力作用下的力学响应,对于研究复合材料的损伤和失效行为有重要意义。研究了聚醚醚酮(PEEK)/碳纤维(CF)单向板偏轴拉伸试件以及加强片的形式。结合理论分析,提出了一种带斜角的加强片形式,并确定了不同偏轴角度下理想的加强片倾斜角度。结合有限元建模分析,对比了不同加强片形式对偏轴拉伸试件的应力场和变形场分布的影响。结果显示,使用方形加强片的试件在偏轴拉伸过程中由于偏轴应力影响,出现应力集中并导致弯曲变形。使用斜形加强片可有效消除试件中的弯矩和应力集中现象。为避免斜形加强片尖端在加载过程中发生脱黏,进一步提出了对斜形加强片尖端进行倒圆角的优化方法,并通过有限元建模分析了优化后加强片附近的应力场分布,与使用未倒角加强片的试件对比发现,对于偏轴角度小于30°的试件,所获得的各方向最大应力相差不大,可采用斜形加强片并倒圆角,以获得更准确的试验数据。该设计有效改善了加强片尖端处的应力集中问题。

再生碳纤维表面处理及其应用

再生碳纤维及其复合材料应用具有很大的环境价值和经济价值。通过制备水性聚氨酯上浆剂并对再生碳纤维进行表面处理,可以有效改善碳纤维表面润湿性,并进一步增强其与热塑性树脂的界面结合。实验结果表明,再生碳纤维经表面改性后,再生碳纤维/ABS树脂基复合材料展现出良好的拉伸强度以及弹性模量。旨在丰富再生碳纤维热塑性树脂基复合材料的相关研究,为后续再生碳纤维表面再构造及其热塑性复合材料制备提供参考依据,有望促进再生碳纤维在工业领域的应用。

复合材料模具在材料成型领域中的发展

如今复合材料的诸多优势已经被慢慢发掘,而随着复合材料的发展,复合材料模具的选择就成为制作高质量复合材料的关键,相比于其他复合材料模具,复合材料模具以其低的热膨胀系数,质量轻、热容小等优点慢慢开始用于制造复合材料,虽然复合材料模具目前仍然存在一些问题,但在将来,随着新材料的发现,成本的降低等,复合材料模具将被广泛运用于制造复合材料产品。

复合材料在船舶上的应用及发展趋势探讨

本文从复合材料的性能特点、分类和应用出发,探讨了其在船舶领域的应用及发展趋势。首先阐述了复合材料在船舶制造和应用中的性能特点,然后从国内和国外两个角度介绍了复合材料在船舶领域的应用现状与主要问题,最后对未来复合材料在船舶领域的发展趋势进行了预测,希望复合材料的应用能为船舶及航海事业发展带来更加优质、可靠的解决方案。

纤维复合相变蓄热材料的固/液界面模拟及分析

按单元结构相似的理论设计了蓄热材料相变传热的物理模型 ,采用焓法理论和有限差分法建立了一种求解此物理模型传热特性的三维数学模型 .利用软件计算结果研究了纤维复合相变材料凝固过程中固 /液界面的移动规律及其放热特性 ,并用摄影法和测温法对纤维相变材料的凝固特性进行了实验论证 ,其结果与理论计算结果吻合 ,从而证明了本文所提出的数学模型的正确性 .

开发高性能复合材料中使用的新型纤维材料

复合材料的性能在很大程度上取决于增强体——纤维的性能、含量及使用状态。主要介绍了几种在开发研制高性能复合材料中使用的新型纤维材料,以及它们的性能、应用与开发动向。

防弹芳纶复合材料实验研究

研究以Ｔｗａｒｏｎ纤维织物为增强材料的复合材料的防弹特性．通过大量实弹试验，初步优化了树脂基体体系，并着重分析了不同树脂基体，不同树脂含量，不同团化压力等对其芳纶复合材料弹道性能的影响，揭示出了一定的规律．所得结果对防弹芳纶复合材料的进一步研究与开发应用有参考价值．

新型胶原基人工皮肤模型的建立

根据皮肤的组织结构与生理功能,研制了复合天然三维网络结构胶原组织工程支架材料,并以此为支架材料建立了3层结构的人工皮肤模型:上层是具有良好生物相容性且可降解的聚合物涂层,可以屏蔽细菌并保持人工皮肤良好的透水气性;中间是复合型天然三维网络结构胶原纤维支架材料层,为细胞的增殖提供三维空间和良好的生长环境,起到真皮基质的作用;下层是药物层,具有营养、抗菌消炎、刺激细胞生长的作用。