本文選題：剪切增稠液體 + 流變性能�。� 參考：《北京理工大學》2015年碩士論文

【摘要】：剪切增稠液體(ShearThickeningFluid: STF)是一種非牛頓液體，在一定的外力作用粘度會急劇增大。STF是新型“液體裝甲材料”的關鍵組分，在阻尼設備方面也有很多重要應用。對STF的性能及其影響因素的研究有利于制備高性能的防護材料和阻尼器件。 本文以氣相SiO2粒子和亞微米級SiO2粒子為分散相，，聚乙二醇（PEG）為分散介質，制備出了不同配比的剪切增稠液體，通過優(yōu)化工藝參數提高了STF的流變性能。通過測試STF的穩(wěn)態(tài)與動態(tài)流變性能，以及在霍普金森壓桿高速加載下的動態(tài)響應規(guī)律，探討了固含量、粒子種類和粒徑等因素對STF性能的影響，并結合高速攝影分析了其相應的影響機理。采用STF浸漬Kevlar纖維織物制得了STF/Kevlar復合材料，對復合材料進行低速沖擊實驗，探討了浸漬液的種類、STF固含量以及面密度等因素對STF/Kevlar復合材料防護性能的影響。得到主要結論如下： （1）固含量、粒子種類、粒徑和粒徑分布等因素均會影響STF的流變性能。固含量、粒徑和粒徑分布均會影響STF的有效體積分數，有效體積分數越高，其黏度越高，臨界剪切速率越小，剪切增稠效應越顯著。對SiO2/PEG分散體系，SiO2粒子和PEG之間的氫鍵作用以及粒子之間的靜電作用是流變性能的內在影響因素。 （2）流體同時具有粘性行為和彈性行為，分別以儲能模量（G′）和耗能模量（G″）來表征。對于剪切增稠體系，G″與G′均會隨著剪切應力提高而增大，而對于非剪切增稠體系，G″則只會發(fā)生小幅度變化，G′則隨剪切應力先急劇減小，然后略微增大，整體表現為下降。 （3）剪切增稠液體在高速加載下發(fā)生了剪切增稠，由液態(tài)轉變?yōu)楣虘B(tài)，具有應力波衰減效應。剪切增稠效應顯著提高了STF的動態(tài)流變應力，剪切增稠效應越顯著，流體的動態(tài)流變應力就越大。強約束條件的施加有利于STF發(fā)生剪切增稠，提高其動態(tài)流變應力。套筒孔徑越大，約束效果越弱，流體動態(tài)流變應力則越小。 （4）剪切增稠液體通過提高纖維摩擦力和纖維間的耦合作用提高Kevlar纖維織物的抗低速沖擊性能，STF種類、SiO2粒徑、固含量和面密度等因素對STF/Kevlar復合材料的抗低速沖擊性能均有影響。固含量影響剪切增稠特性，粒徑和STF種類則同時影響纖維摩擦力和剪切增稠特性。STF剪切增稠效應越顯著，越有利于纖維之間的耦合和載荷傳遞，以及STF/Kevlar復合材料的抗低速沖擊性能的提高。
[Abstract]:Shear thickening liquid Shearding fluid: STF is a kind of non-Newtonian liquid. The viscosity of shear thickening liquid increases sharply under a certain external force. STF is a key component of a new type of "liquid armored material" and has many important applications in damping equipment. The study of the properties of STF and its influencing factors is beneficial to the preparation of high performance protective materials and dampers. In this paper, SiO2 particles and submicron SiO2 particles were used as dispersed phase and polyethylene glycol (PEG) as dispersing medium to prepare shearing thickening liquid with different ratios. The rheological properties of STF were improved by optimizing the process parameters. By testing the steady and dynamic rheological properties of STF and the dynamic response of Hopkinson compression bar under high speed loading, the effects of solid content, particle type and particle size on the properties of STF were discussed. Combined with high-speed photography, the influence mechanism is analyzed. The STF/Kevlar composites were prepared by impregnating Kevlar fiber fabric with STF. The low speed impact tests were carried out on the composites. The effects of the type of impregnating solution and the surface density on the protective properties of STF/Kevlar composites were discussed. The main conclusions are as follows: (1) solid content, particle type, particle size and particle size distribution all affect the rheological properties of STF. Solid content, particle size and particle size distribution all affect the effective volume fraction of STF. The higher the effective volume fraction, the higher the viscosity, the smaller the critical shear rate and the more significant the shear thickening effect. The hydrogen bond interaction between SiO2 particles and PEG and the electrostatic interaction between PEG particles in SiO2/PEG dispersion system are the internal factors affecting the rheological properties. (2) the fluid has both viscous and elastic behaviors, which are characterized by the energy storage modulus (G) and the energy dissipation modulus (G "), respectively. For shear thickening system, both G "and G 'will increase with the increase of shear stress, while for non-shear thickening system G" will only change by a small margin. Overall performance is down. (3) Shear thickening of shear thickening liquid occurs under high speed loading, which changes from liquid state to solid state, and has the effect of stress wave attenuation. The effect of shear thickening significantly increases the dynamic rheological stress of STF, and the more obvious the effect of shear thickening, the greater the dynamic rheological stress of fluid. The application of strong constraint conditions is beneficial to the shear thickening of STF and to increasing its dynamic rheological stress. The larger the diameter of the sleeve is, the weaker the confinement effect is, and the smaller the dynamic flow stress of the fluid is. (4) Shear thickening liquid can improve the low speed impact resistance of Kevlar fiber fabric by increasing the friction force and the coupling effect between fibers. The particle size, solid content and surface density of Kevlar fiber fabric have effects on the low speed impact resistance of STF/Kevlar composites. Solid content affects shear thickening, particle size and STF type affect fiber friction and shear thickening at the same time .STF shear thickening effect is more significant, which is more favorable to fiber coupling and load transfer. And the improvement of low speed impact resistance of STF/Kevlar composites.
【學位授予單位】：北京理工大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TB33;TQ340.1

【參考文獻】

相關期刊論文 前7條

1 黃獻聰;;防彈防刺材料的研究與技術發(fā)展[J];紡織導報;2013年01期

2 姜會平;王曉川;鐘發(fā)春;孫毅;劉勇;;單分散納米SiO_2微球表面化學修飾及STF效應研究進展[J];化工新型材料;2010年12期

3 伍秋美;阮建明;黃伯云;周忠誠;鄒儉鵬;;低固相含量SiO_2分散體系流變性研究[J];化學學報;2006年15期

4 伍秋美;阮建明;周忠誠;黃伯云;;SiO_2/聚乙二醇非牛頓流體流變性能研究[J];物理化學學報;2006年01期

5 伍秋美;阮建明;黃伯云;周忠誠;鄒儉鵬;;二氧化硅分散體系在應力剪切過程中粘彈性及能耗研究[J];物理化學學報;2006年09期

6 程平;周蘭英;王玉猛;;剪切增稠流體STF試驗研究[J];中國科技信息;2006年05期

7 段先健;吳利民;張翼;;氣相二氧化硅的表征方法[J];有機硅氟資訊;2003年11期

本文編號：1828187