【摘要】：在我國高緯度的東北、西北等地區(qū),由于冬季寒冷引起河流大面積結(jié)冰導(dǎo)致的水工建筑物損壞的事情經(jīng)常發(fā)生,會引起巨大的經(jīng)濟(jì)損失。因此研究冰力學(xué)特性,了解冰形成和融化過程中力的變化十分必要,可以為水工建筑的防護(hù)與建造提供指導(dǎo)。隨著光纖技術(shù)的發(fā)展,光纖傳感技術(shù)因其結(jié)構(gòu)簡單、不受電磁干擾、體積小、靈敏度高等優(yōu)點(diǎn),自誕生約50年以來得到了十分迅速的發(fā)展,目前已應(yīng)用于生產(chǎn)和生活的許多方面。光纖環(huán)衰蕩(FLRD)技術(shù)是以腔衰蕩光譜(CRDS)技術(shù)為基礎(chǔ)提出的,利用光纖環(huán)形成諧振腔的一種強(qiáng)度型光纖調(diào)制技術(shù)�；贔LRD技術(shù)的光纖傳感器還具有穩(wěn)定性和實(shí)時(shí)性好、響應(yīng)速度快等優(yōu)點(diǎn)。本文結(jié)合FLRD技術(shù)與光纖微彎傳感技術(shù),設(shè)計(jì)了一種連續(xù)監(jiān)測靜冰壓力的傳感系統(tǒng)。論文的主要工作包括:(1)通過查閱文獻(xiàn)資料,綜述了靜冰壓力的研究現(xiàn)狀,介紹了幾種常用的靜冰壓力估算方法,并對光纖傳感的基本原理和分類進(jìn)行了介紹。(2)介紹了CRDS技術(shù)及FLRD技術(shù)基本結(jié)構(gòu)、原理及發(fā)展歷程。FLRD技術(shù)包含脈沖光源、光纖環(huán)和數(shù)據(jù)處理部分。脈沖光源使用實(shí)驗(yàn)室搭建的摻鉺光纖環(huán)形鎖模激光器;光纖環(huán)由兩個(gè)分光比為95:5的2×1耦合器和一段單模光纖組成;數(shù)據(jù)處理部分包含光電探測器和示波器。FLRD技術(shù)把傳統(tǒng)強(qiáng)度傳感器測量光強(qiáng)轉(zhuǎn)換為測量脈沖在光纖環(huán)中的衰蕩時(shí)間,避免光源強(qiáng)度變化引起所測物理量的誤差。(3)通過分析光纖彎曲損耗理論和討論微彎傳感器的靈敏度,設(shè)計(jì)了適用于靜冰壓力測量的微彎傳感器結(jié)構(gòu),并利用3-D打印機(jī)制作實(shí)驗(yàn)時(shí)所用的微彎傳感器。(4)基于FLRD原理,結(jié)合光纖微彎傳感器,設(shè)計(jì)了一種用于靜冰壓力測量的光纖傳感器。利用此系統(tǒng)結(jié)合高低溫交變濕熱試驗(yàn)箱測量了-10℃~6℃條件下冰的形成和融化過程中靜冰壓力隨著溫度變化的曲線。傳感器達(dá)到0.00998/(μs·kPa)的精度,測得最大冰壓力為(552±4)kPa。實(shí)驗(yàn)證明,此傳感系統(tǒng)可以對冰形成和融化過程的靜冰壓力變化進(jìn)行實(shí)時(shí)和連續(xù)監(jiān)測。
[Abstract]:In the northeast and northwest of China in the high latitudes, the damage of hydraulic structures caused by the freezing of large areas of rivers in winter often occurs, which will cause huge economic losses. Therefore, it is necessary to study the mechanical properties of ice and understand the change of force during ice formation and melting, which can provide guidance for the protection and construction of hydraulic buildings. With the development of optical fiber technology, optical fiber sensing technology has been developed rapidly since its birth 50 years ago, because of its simple structure, no electromagnetic interference, small size, high sensitivity and so on. At present, it has been applied in many aspects of production and life. The optical fiber ring ring-down (FLRD) technique is based on the cavity ring-down spectrum (CRDS) technique, which is a kind of intensity-type optical fiber modulation technique which uses the fiber ring to form the resonator. The optical fiber sensor based on FLRD technology also has the advantages of good stability, real-time, fast response speed and so on. In this paper, a continuous monitoring system of static ice pressure is designed based on FLRD technology and fiber optic microbend sensing technology. The main work of this paper is as follows: (1) the research status of static ice pressure is summarized, and several commonly used static ice pressure estimation methods are introduced. The basic principle and classification of optical fiber sensing are introduced. (2) the basic structure, principle and development of CRDS and FLRD technology are introduced. FLRD technology includes pulse light source, optical fiber loop and data processing. The pulse light source is composed of two 2 脳 1 couplers with a splitting ratio of 95:5 and a single mode fiber, which is made up of an erbium-doped fiber ring mode-locked laser. The data processing part includes photodetectors and oscilloscopes. FLRD technology converts the traditional intensity sensor to measure the time of pulse decay in an optical fiber ring. (3) by analyzing the theory of optical fiber bending loss and discussing the sensitivity of micro-bending sensor, the structure of micro-bend sensor suitable for static ice pressure measurement is designed. The microbend sensor used in experiment is fabricated by 3-D printer. (4) based on the principle of FLRD, a fiber optic sensor for measuring static ice pressure is designed. Using this system, the curves of static ice pressure and temperature change during ice formation and melting at -10 鈩，

本文編號：2304164