本文選題：模壓成形 + 非球面　； 參考：《湘潭大學》2017年碩士論文

【摘要】：光學元件在現(xiàn)代社會中起著重要的作用,用于娛樂、通信、制造和測量的光電裝置被廣泛使用,其中非球面玻璃透鏡因為能夠有效修正影像畸變、色差、慧差,改善成像質(zhì)量、簡化儀器結(jié)構(gòu)而備受關(guān)注。相比于傳統(tǒng)的去除加工方法,玻璃模壓成形技術(shù)具有高效率、低成本、適合大批量生產(chǎn)等優(yōu)點,模壓成形獲得的透鏡無需后續(xù)拋光處理就可以直接使用。但是該技術(shù)在實際生產(chǎn)中存在兩個難題:其一是成形透鏡內(nèi)部容易產(chǎn)生較大的殘余應力,使成形透鏡表面產(chǎn)生裂紋甚至破裂,影響其光學性能及使用壽命;其二是成形透鏡的最終成形輪廓與原設(shè)計輪廓之間存在較大的成形誤差。為了解決這些問題,本文使用Msc.Marc有限元分析軟件建立了非球面凹凸玻璃透鏡的數(shù)值模型,對成形透鏡的殘余應力及成形誤差分別進行仿真預測,并通過模壓成形實驗來驗證仿真預測結(jié)果的有效性,之后通過改變單一成形參數(shù)來研究其對殘余應力和成形誤差的影響規(guī)律。主要研究工作如下:1.基于廣義Maxwell模型,分別建立加熱、模壓、退火和冷卻四個階段的數(shù)值模型,對整個成形過程中透鏡的殘余應力進行預測。預測結(jié)果表明透鏡的殘余應力主要集中于凹、凸面內(nèi)側(cè),凹、凸面的最大殘余應力都出現(xiàn)在拐點附近且凹面大于凸面,退火過程能夠有效消除透鏡內(nèi)部的殘余應力。通過進行模壓成形實驗,測量了非球面凹凸玻璃透鏡的殘余應力,測量結(jié)果與預測結(jié)果相吻合,驗證了仿真預測的有效性。2.在仿真預測與實驗相結(jié)合的基礎(chǔ)上,研究了各成形參數(shù)對殘余應力的影響規(guī)律,結(jié)果表明:在模壓階段,透鏡的殘余應力與模壓溫度成反比關(guān)系,與模壓速率、摩擦系數(shù)成正比關(guān)系;退火階段,透鏡的殘余應力與退火速率及保壓力皆成正比關(guān)系;冷卻階段,冷卻速率對殘余應力并無明顯影響。3.分析模壓成形過程中造成成形誤差的原因,成形誤差主要出現(xiàn)在三個方面:1)模具成形腔表面的加工誤差;2)模壓階段玻璃預形體復制熱變形模具輪廓而產(chǎn)生的誤差;3)退火階段透鏡結(jié)構(gòu)松弛產(chǎn)生的誤差。在此基礎(chǔ)上,對透鏡在成形過程中產(chǎn)生的成形誤差進行預測,并對實驗所獲得的非球面凹凸玻璃透鏡表面輪廓進行測量,測量結(jié)果與預測結(jié)果相吻合,表明了通過數(shù)值仿真來預測透鏡成形誤差的可行性。4.通過改變單一的成形參數(shù)來研究其對成形誤差的影響規(guī)律。結(jié)果表明,成形誤差隨著模壓速率的增大而增大,隨著模壓溫度的增大而減小,但過高的模壓溫度會使成形誤差變大,成形誤差隨著退火速率、保壓力、摩擦系數(shù)的增大而減小,冷卻速率對成形誤差無明顯影響。
[Abstract]:Optical elements play an important role in modern society, and optoelectronic devices used for entertainment, communication, manufacture and measurement are widely used. Among them, aspheric glass lenses can effectively correct image distortion, color aberration, and improve imaging quality. Simplification of the instrument structure has attracted much attention. Compared with the traditional removal process, the glass die forming technology has the advantages of high efficiency, low cost and suitable for mass production. The lens obtained by die forming can be used directly without subsequent polishing. However, there are two problems in the practical production of this technology: one is that the forming lens is prone to produce large residual stress, resulting in cracks or even rupture on the surface of the formed lens, which affects its optical properties and service life; The other is that there is a large forming error between the final profile of the forming lens and the original design profile. In order to solve these problems, the numerical model of aspheric concave convex glass lens is established by using the finite element analysis software Msc.Marc. The residual stress and the forming error of the forming lens are simulated and forecasted respectively. The effectiveness of simulation prediction is verified by die forming experiment, and the influence law of residual stress and forming error is studied by changing a single forming parameter. The main research work is as follows: 1. Based on the generalized Maxwell model, the numerical models of heating, moulding, annealing and cooling are established, and the residual stresses of the lens in the whole forming process are predicted. The prediction results show that the residual stresses of the lens are mainly concentrated in the concave, inner, concave and convex sides of the lens, and the maximum residual stresses of the concave and convex surfaces appear near the inflection point and the concave surface is larger than the convex surface. The annealing process can effectively eliminate the residual stress in the lens. The residual stress of aspherical concave convex glass lens is measured by die forming experiment. The results are in good agreement with the predicted results, and the validity of the simulation prediction is verified. 2. On the basis of simulation and experiment, the influence of various forming parameters on residual stress is studied. The results show that the residual stress of the lens is inversely proportional to the molding temperature and to the molding rate during the molding stage. The friction coefficient is proportional to the coefficient of friction, the residual stress of the lens is proportional to the annealing rate and the holding pressure in the annealing stage, and the cooling rate has no obvious effect on the residual stress at the cooling stage. The causes of forming errors in the process of die forming are analyzed. The forming error mainly appears in three aspects: 1) machining error of mold cavity surface 2) error caused by glass preform copying hot deformation die profile during molding stage and 3) error caused by lens structure relaxation in annealing stage. On this basis, the forming error of the lens in the forming process is predicted, and the surface profile of the aspherical concave convex glass lens obtained by the experiment is measured. The measured results are in good agreement with the predicted results. The feasibility of predicting lens forming error by numerical simulation. The influence of single forming parameters on forming error is studied. The results show that the forming error increases with the increase of the molding rate and decreases with the increase of the molding temperature. However, the forming error increases with the annealing rate and keeps the pressure when the molding temperature is too high. With the increase of friction coefficient, the cooling rate has no obvious effect on the forming error.
【學位授予單位】：湘潭大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TH74;TQ171.734

【參考文獻】

相關(guān)期刊論文 前10條

1 陳慶;尤若寧;毛坤劍;周文光;;一種醫(yī)用眼鏡式放大鏡的設(shè)計[J];中國醫(yī)療設(shè)備;2016年11期

2 尹韶輝;朱科軍;余劍武;朱勇建;陳逢軍;;小口徑非球面玻璃透鏡模壓成形[J];機械工程學報;2012年15期

3 劉衛(wèi)國;沈萍;;硫系玻璃的粘彈性及模壓工藝的仿真[J];紅外與激光工程;2012年03期

4 尹韶輝;霍建杰;周天豐;朱科軍;王玉方;靳松;余劍武;;小口徑非球面透鏡模壓成形加熱加壓參數(shù)仿真[J];湖南大學學報(自然科學版);2011年01期

5 馬韜;余景池;王欽華;;小口徑薄型玻璃透鏡精密模壓制造[J];紅外與激光工程;2011年01期

6 尹韶輝;王玉方;朱科軍;霍建杰;陳逢軍;余劍武;王宇;;微小非球面玻璃透鏡超精密模壓成型數(shù)值模擬[J];光子學報;2010年11期

7 蔣亞絲;;光學玻璃進展(五)[J];玻璃與搪瓷;2010年05期

8 尹韶輝;靳松;朱科軍;陳逢軍;余劍武;;非球面玻璃透鏡模壓成型的有限元應力分析[J];光電工程;2010年10期

9 陳t，

本文編號：2084132