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Fracture Mechanics Study for Toughening Fiber Reinforced Composites

增韧纤维增强复合材料断裂力学研究

基本信息

批准号：
08650085
负责人：
HASHIDA Toshiyuki
金额：
$ 1.47万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08650085/
关键词：
Composite Distributed Microcracking Material Fracture Mechanics Material Design Model Sparle Plasma Sintering Method Ceramics Fiber Toughening 高靱化

项目摘要

The objective of this research is firstly to develop a fracture mechanics based micromechanical model for the design of pseudo strain hardening composites reinforced with random discontinuous and aligned continuous fibers, and then to propose a method for optimizing the strength and the toughness of composites on the basis of themicromechanical model. The following tasks form major subjects of this research.Task (1) Development of Design ModelWe developed a micromechanical model which provides a link between the composite properties (strength and toughness) and the composite parameters (fiber parameters : dimensions, volume fraction and mechanical properties ; matrix parameters : toughness and elastic moduli ; interface shear strength ; snubbing coefficient). The model is applicable to both the cases of fiber pull-out and fiber rupture.Task (2) Preparation and Evaluation of Fiber Reinforced CompositesUsing a spark plasma sintering method, we prepared continuos carbon fiber reinforced SiC composites and LAS/wolastonite composites reinforced with short random fibers of a 304 type stainless steel. It was shown by conducting three point bend tests that the micromechanical model has a capability of predicting the mechanical properties of the prepared composites. Furthermore, the LAS/wolastonite composites were shown to produce pseudo strain hardening behavior.Task (3) Optimization of Composite ParametersBased on the micromechanical model, we devised a design chart which embodied the conditions for pseudo strain hardening, uniform fiber distribution, and fiber rupture. Finally, we proposed a methodology of optimizing the fiber parameters for high toughness composites by conducting parametric studies.

本研究的目的是建立一个基于断裂力学的细观力学模型，用于随机不连续和取向连续纤维增强伪应变硬化复合材料的设计，并在此基础上提出一种优化复合材料强度和韧性的方法。任务(1)设计模型的开发我们开发了一个细观力学模型，该模型提供了复合材料性能(强度和韧性)与复合材料参数(纤维参数：尺寸、体积分数和机械性能；基质参数：韧性和弹性模数；界面剪切强度；抑制系数)之间的联系。该模型适用于纤维拔出和纤维断裂两种情况。任务(2)纤维增强复合材料的制备与评价采用放电等离子烧结法制备了连续碳纤维增强碳化硅复合材料和无规短纤维增强硅灰石/硅灰石复合材料。三点弯曲试验表明，该细观力学模型具有较好的预测复合材料力学性能的能力。任务(3)复合材料参数的优化在细观力学模型的基础上，我们设计了一个包含准应变硬化、纤维均匀分布和纤维断裂条件的设计图。最后，通过参数研究，提出了优化高韧性复合材料纤维参数的方法。