东华大学纤维集合体力学2017年期中考试试题

2017~ 2018学年第 1 学期研究生期中考试试题
考试学院：纺织学院
考试专业：修习本课程硕士生
考试课程名称：纤维集合体力学
（考生注意：答案必须写在答题上，写在本试题纸上一律不给分）
[试题部分]
[注]: 本试卷共计8大题，均为必答题。

满分100分。

命题人顾伯洪
一 (10)
二 (10)
三 (10)
四 (10)
五 (10)
六 (10)
七 (10)
八 (10)
九 (10)
十 (10)
总分
2017~ 2018学年第 1 学期研究生期中考试试题
考试学院：纺织学院
考试专业：修习本课程硕士生
考试课程名称：纤维集合体力学
（考生注意：答案必须写在答题上，写在本试题纸上一律不给分）[试题部分]
1 (10’s)
Fig.1 Structure of wool fibre, as drawn by Robert C. Marshall, CSIRO, Melbourne
As shown in Fig.1 for the multi-scale structure model of wool fiber:
(1) Describing the molecular configuration and molecular chain conformation;
(2) Explaining the multi-scale structure mechanisms for the wool fiber crimp shape.
2 (10’s)
Fig.2 Morphological structure of the cotton fibre For cotton fiber structure as shown in Fig.2,
(1) Presenting the sketch for the multi-scale structure;
(2) The moisture absorption mechanisms from the multi-scale structure.
3 (10’s)
Fig.3 Structure of a para-aramid fibre (Kevlar) with radial pleat.
For para-aramid fibre (Kevlar) in Fig,3
(1) using the viscoelastic constitutive equation to calculate the energy absorption under cyclic loading
0101sin t (where >)σσσωσσ=+.
(2) predicting the failure time under the cyclic loading. 4 (10’s)
Fig.4 Elastic energy U E and plastic energy U P after load-cycling for the partially oriented nylon fibre.
For the load-elongation curve of nylon fiber shown in Fig.4, (1) repeating the two questions in the above-mentioned Item 3.
(2) what are the differences mechanisms for the nylon and Kevlar fibers?
Deformation at points of real contact, showing welded junctions
Fig .5 Effect of friction by platinum slider on nylon monofilament at low load and high load For the fiber friction, presenting the sketch for the surface friction damage initiation and friction force development mechanisms from fiber surface morphology and multi-scale structure.
Fig.6 Compression of fiber assemblies
Fig.6 depicts compression and inflation of fiber assemblies. To calculate the energy and deformation of compression and inflation.
7 (10’s)
Fig.7 Tracer fiber and filament yarn
For the Yen’s tracer fiber technique and filament yarn structure model in Fig.7.
(1) How to describe the filament fiber trajectory with Yen’s tracer fiber technique,
(2) Using the energy method to calculate the energy absorption of the filament yarn under tension.
8 (10’s)
Fig.8 Woven fabric shear and shear model
Using the warp-weft yarn contact model in Fig.8, to calculate the shear stiffness of woven fabric.
9 (10’s)
Fig.9 Warp-knitted structure
To present the methodology flow chart to calculate the tensile stiffness of warp-knitted structure in Fig.9
10 (10’s)
Fig.10 Typical bending curve of fabric
From structure-properties relationships, to compares the differences of bending behaviors between knitted and woven structures.。