SUPERVISOR
Yaghoob Tadi bani,Seyed-Abdolkarim Hoseini
یعقوب طادی بنی (استاد مشاور) سیدعبدالکریم حسینی (استاد راهنما)
STUDENT
Zahra Tadi beni
زهرا طادی بنی
FACULTY - DEPARTMENT
دانشکده مهندسی نساجی
DEGREE
Doctor of Philosophy (PhD)
YEAR
1391
TITLE
Theoretical(non-classical continuum theory)and experimental study of piezoelectric properties PVDF nanofiber web
By developments in the nanoscience and the creation of nanobeams, nanoplates, application of these components has grown widespread in micro and nano structures, such as micro-electro-mechanics and nano-electronics, due to their mechanical, chemical, and electronic properties, and these components have attracted the attention of many researchers as energy harvester. Therefore, today, the study of the mechanical properties of nanostructures due to their increasing use has become specifically important. On the other hand, due to the small dimensions of nanostructures and some of the fractures, there are differences between the modeling of these structures and the macro structures. To study the nanostructures, the use of atomic testing or modeling, like molecular dynamics, is appropriate. However, since testing and controlling it in nanoscale dimensions is very costly and methods, such as molecular dynamics, are costly, researchers are now seeking to model nanostructures with theories of mechanics of non-classic continuum model. For this reason, as the mechanics of classic-continuum model makes error in predicting the behavior of these structures due to the lack size effect, the use of higher order theories such as couple stress theory been expanded as they can take into account the effect size in the calculations. The results showed that comprehensive and complete modeling of porous, viscoelastic, and orthotropic piezoelectric sizedependent plate structures at the nanoscale has not been performed so far. Therefore, in this study, the main purpose of the model is to model the energy-harvesting plate structure produced by polyvinylidine-fluoride nanofibers with piezoelectric viscoelastic properties. Obviously, the results of this study will be able to provide a good understanding of the prediction behavior of energy harvesting structures with these properties. To achieve this, two-dimensional, viscoelastic and piezoelectric thin plate models were used with von Karman displacement field. In the experimental section, to evaluate the proposed model, an attempt was made to produce a piezoelectrically nanofibers sample by polyvinylidene fluoride polymer. Initially, the experimental design was performed using response surface methodology and the most important parameters affecting the electrospinning process were extracted from four independent parameters of concentration, voltage, feed rate and roller speed. The results of the experimental design showed the effect of the roller speed parameter on the intensity of the piezoelectric property. Different morphological and microstructural characterizations were performed to better understand and understand the behavior of nanofluid structures produced at different rolling speeds. The results of small angle X-ray diffraction showed good beta phase formation for all samples and Fourier spectroscopy was used to investigate the crystal structure of the samples. Scanning electron microscopy also determined the fiber arrangement and diameter. Investigation of fiber structure showed a decrease in diameter and improved uniformity of fibers with increasing rotational speed of harvesting roller and the piezoelectric output response increased with increasing fiber fineness with increasing arrangement. The output voltage response at constant force and frequency was recorded for all samples by a piezoelectric property analyzer. The maximum fiber arangement percentage was 87% at 2000 rpm and the porous nano web with 57% porosity had the highest output voltage response of 14 mV/N. The theoretical model output voltage response intensity for the selected sample was 12 mV/N. The results show that there is good agreement between experimental data and modeling.
ثف?ا زٌ ا ف?ل 2 اق ،? ط? 5 ف?ب? 2 اوز و? اق ??ر?ب لجُ ??? س?خ? ث??? اوز، ا ب? ا ف??ق? ثب افکا 4 ف?ٍا 3??ب 2 ق 4ىز ط? 5? 3 ? وب?ً ??بث? ا ف?ل 2 ? ?وشفن ? ? س?? 5? افکا 4ً اوشفب?? ?ق افک?? اق اثکا ا ىِشف? 5?ه لبثُ ض ،?ُ ا 4? ف?ب? 2 ث 5ً اق د 5ً ا? 5?ز 4بفش? اوز. ? و 5ىش ??ب 2 ا ىِشف? ى?ب 5?ى 3، ضى فٍ?ب ? ب? ??ل ??اس??ب اق ب? ?? س 5ف ? ب? ?? ?ق?ب ث? 0??ا وبق? ثف?ا زٌ و??? ا ف?ل 2 اوشفب?? 3? ?ٌ?. د 5 ث 5? 3 فشب ا 4 وبق??ب، ثب ا د?ب آق ب? 4 بٍر سدفث 3 ثى 5ب ى?ٍ 3?ثب ?ٌ، اق ا 4 ?? ثب اوشفب?? اق ?? وَبق 2 وبق??ب 2 ب? ?? 34 و 31 ? فِف?خ? 34 ? ق ب? ? ?ک 4?? 3?ثب ?ٌ. ثفو 3?ب ب?ٍ ?ا?? اوز و? ?? وَبق 2 خب ?? ? وب اق وبق? فِط?ا 2 د 5ک?ا ىِشف 4ه ش?? ?ّ ، ? 4ىى?الاوش 5ه ? ??وب ف?ٍ? ثب ? ??ف فٌفش اثف ا ??اق? ? اث 1ب? ب? ?? سبو?? ?ِر ذ?? 4ففش? اوز، ?ِا ? ا 4 سطم 5ک ??ف ا 3ِّ ?? وَبق 2 وبق? فِط?ا 2 ثف?ا زٌ و??? ا ف?ل 2 س? 5ِ? ?ٌ? س?و ب? ?? ا 5ِبف د 3ّ? 4? 5ّ 5 ? 4 ف? ?ّا 4? ثب غب 5ِز د 5ک?ا ىِشف 4ه ? 4ىى?الاوش 5ه ??وب ف?ٍ? 3?ثب ?ٌ. ث? 4? 3 اوز و? ش?ب 4ح ضبُِ اق ا 4? سطم 5ک، لب? ث? اائ? ?ن ?? ?ّث 3 اق د 5 ث 5? 3 فشب وبق? ثف?ا زٌ ا ف?ل 2 ثب غ?ا ??و? غ?ا?? ث??. ثفا 2 ?وش 5بث 3 ث? ا 4 ا ف?، ?? ?ق ب?قن ??وب ف?ٍ?، ? 4ىى?الاوش 5ه ? د 5ک?ا ىِشف 4ه ثب اضشىبة 5??ا خبثدب 34 ? وب اوشفب?? فٌ? 4? ? ثب اوشفب?? اق سئ? 2 ضبج اوف?? 4ب 2 ثفا 2 ??ا? د 5ک?ا ىِشف 4ه ? ا ? 5? شّ? 1?ب?لار ? 4ففا ى? 5 خکئ 3 ث? 1?ب?لار ? 4ففا ى? 5 دب? ا 2 1?ب?لار ضفوز اوش?فاج ?ٌ ??. وذه ثب اوشفب?? اق ?ی بٌ فِو 5 1?ب?لار ض سج? 4 ?ٌ ?? ? ثب اوشفب?? اق ?ی اغش بٍ 3ٌ ز?? م? 5بو 3 ثفا 2 فٌ ف?ق 2 ??وف 5ٌف?ا ? ثب و ه? ف? افکا 55? فٌ? 4? ??. دبوع اوش?فاج ?ٌ?، دبوع ? 4?ب 5?ى 3 فِط? ??وب ف?ٍ? ش?? ?ّ د 5ک?ا ىِشف 4ه ? 4ىى?الاوش 5ه 3?ثب ?ٌ . 4بفش? ثب غب 5ِز د 5ک?ا ىِشف 4ه س?و ? ث? سدفث 3 خ?ز اق 4بث 3 ?? اائ? ?ٌ?، و 31 ? س? 5ِ? ??? ?? ب? ??ا 5ِبف 3 آا 4 د 5ّ ف? د 3ّ ? 4? 5ّ 5 ? 4 ف ?ّا 4? ث??? اوز. ? اثش?ا ف?اض 3 آق ب? 4 ثب اوشفب?? اق ?ی و?ص ? 4? دبوع ا د?ب فٌ? 4? ? ?? ش?ف 4 دبا ش?ف اثف ?ٌا ففا 4?? ا ىِشف? 4ى 3 اق 5?ب ز?ب دبا ش?ف ى?شم غ ?ّز، ? شِبل، ف?ظ سغ? 4? ? وف 0ز غ شّه ثف?ا زٌ اوش?فاج فٌ? 4?. اق ش?ب 4ح ث? ?وز آ ??? اق ف?اض 3 آق ب? 4 ،ً اثف دبا ش?ف وف 0ز غ شّه ثف?ا زٌ ثف ? 2 ?ٌر غب 5ِز د 5ک?ا ىِشف 4ه ??ٍ?? ث??. ??? ?? ??? ??ف ثفا 2 م?ب 4ى? ثب ش?ب 4ح سئ? 2 س?و فٌا 4 ا ىِشف? 4ى 3 د 5 ?ٍ?ب? ?ٌ? س?و ?ی آ ب? 2 و?ص ? 4? دبوع س? 5ِ? فٌ? 4?. ??ٍ ?ّ 4بث 3?ب 2 ??شفّ ??ف? ?ِل 4ى 3 ? 4کوبغشب 2 ثفا 2 ف?? ? ?ن ث?شف فشب وبق??ب 2 ب? ?? 5ِف 3 س? 5ِ? ?ٌ? ثب وف 0ز ??شفّ غ شّه ثف?ا زٌ، ?ِر فٌفز. ش?ب 4ح دفای ا 1ٌ? ا 4ىه قا? 4? و?زه ثفا 2 س ب? 3? ??? ???ب س ىٍ 5 فبق ثشب ا ث? غ?ث 3 ب?ٍ? ?ا? ? 5?ف و?د 3 ف? 4? خ?ز ثفو 3 وبغشب ث ?ّ 2 ??????ب اوشفب?? ?ٌ. ثب 0ىه ثف?ا 2 4بفش 3ٍ ? ل?ف ا 5ِبف س 551 فٌ? 4?. ثفو 3 5?ک ز ?ٍ 3?ٍ آا 4 س?و 5?ىف?وى?ح ا ىِشف? 3? ?ث 3ٍ وبغشب ا 5ِبف ضبو 3 اق وب?ً ل?ف ? ث?ج?? 4ى??اغش 3 ا 5ِبف س? 5ِ? 2 ثب افکا 4ً وف 0ز ??ا 3? غ شّه ثف?ا زٌ ث?? ? دبوع غف?خ 3 د 5ک?ا ىِشف 4ه 5?ک 4بفش 3ٍ، افکا 4 ا ب?ٍ ?ا?. دبوع ? شِبل غف?خ 3 ? 5?ف? ? ففوبه? ثبثز ثفا 2 ثب افکا 4 ?فافز ا 5ِبف س?ا ثب افکا 4 آا 4 س ب? 3? ??? ???ب س?و ?وش بٍ? س 551 غب 5ِز د 5ک?ا ىِشف 4ه ثجز ? ج? فٌ? 4?. ب?وک 4?? ? ?ِ آا 4ً 4بفش 3ٍ ا 5ِبف ثفاثف ثب 87 % ? وف 0ز ثف?ا زٌ 2000 ?? ثف ?ل 5م? ث? ?وز آ ?? ? ب? ?? ?ة ش?? ?ّ ثب ? ?ِ س? ?ّ 57 ? ?ِ ث 5 شٍف 4 ?ٌر دبوع ? شِبل غف?خ 3 ا ?ا زٌ. ش?ب 4ح سئ? 2 ? سدفث 3 ثفا 2 ثفو 3 اثف س? ?ّ ،ُ م??ا 5?ف? 2 ?ا?? ثف ??? ?? ? ففوبه? سطف 4ه ثب 4ى? 4 فٍ م?ب 4ى? ?ٌ ?? ? ? ?? ب?ٍث? 3 ثفا 2 آ ??ب طِب? فٌ? 4?. ?ٌر دبوع ? شِبقغف?خ 3 ?? سئ? 2 ثفا 2 ??? ?? ث? 5??، م??ا 3ّ 5? ?زِ ثف 5??س ث?وز آ ?? ? ?ٌر دبوع ثفا 2 ??? ?? ?ة ب? ?? 5ِف 3 ??و? م??ا 3ّ 5? 14 ?زِ ثف 5??س ا ب?ٍ ?ا?. 12 ث?بثفا 4 ا ??جبق غ?ث 3 ث 5? ?ا???ب 2 سدفث 3 ? ?? وَبق 2 اق طِب? ?ٌر دبوع ? شِبل غف?خ 3 ب?ٍ??? ?ٌ.