明膠玻璃溫間拉伸成形之研究

Abstract

飛機的明膠玻璃風檔傳統上是以人工或低程度自動化的方式生產，為了優化相關領域的製程與品質，本論文研究旨在建立明膠玻璃溫間拉伸成形製程之CAE分析模型，並藉由材料特性、製程參數和光學表現的初步探討了解影響風檔產品的各項因素，以供相關製程參考與應用。 透過文獻的蒐集和研究，本論文對明膠玻璃材料的特性和行為有了深入的了解，並成功建立了超黏彈材料模型的CAE模擬模型，並以實體元素搭配隱式(Implicit)運算方式進行模擬分析，但仍待實際製程機台之驗證。 在材料特性方面，本研究進行了明膠玻璃材料的高溫拉伸實驗、界面摩擦實驗、界面熱傳實驗，而熱膨脹和高溫潛變性質則藉由文獻數據的蒐集和比較進行分析。這些實驗結果提供了重要的材料參數數據資料，也藉由材料拉伸模擬驗證了CAE材料模型之正確性，這有助於更準確地模擬明膠玻璃材料在高溫成形過程中的變形與反應，也為CAE模型之正確性提供了初步的驗證。 在製程參數方面，本論文研究了夾爪型態與作動軌跡、冷卻時間和不等寬下料等參數對成形結果的影響。通過模擬和分析，歸納出夾爪間之空隙越小對於成形情況越好；而夾爪速度隨時保持與板材邊緣垂直，不僅可以讓成形後的殘留應力更小，也對厚度的成形品質有良好效果。此外也發現冷卻階段能進一步讓應力釋放，但效果僅至70℃以上。至於針對不等曲率造型之製程，以不等寬下料方式可以有效改善成形結果且調整難度相對較低。 在光學表現方面，透過蒐集相關的光學理論和文獻，初步分析了光學表現如影像扭曲以及色散問題與成形指標間的對應性，包括厚度分佈、殘留應力分佈和密度分佈等參數對光學性能的影響。此外也評估出風擋光學表現由電腦自動化檢測是目前最好的方式。 本論文之研究內容可提供未來相關製程之分析或優化作為參考。

Traditionally, the acrylic glass windshields of airplanes were produced by manual or low-level automation. In order to optimize the process and quality in related fields, this thesis aimed to establish a CAE analysis model for the acrylic glass thermo-stretch forming process. Through preliminary exploration of material properties, process parameters, and optical performance, various factors affecting windshield products were understood for reference and application in related processes. Through literature collection and research, this thesis gained an in-depth understanding of the characteristics and behavior of acrylic glass materials and successfully established a CAE simulation model for the superelastic material model. The simulation analysis was carried out using solid elements in conjunction with implicit calculation methods, but still awaited verification by actual process equipment. In terms of material properties, this study conducted high-temperature stretching experiments, interface friction experiments, and interface heat transfer experiments on acrylic glass materials. The thermal expansion and high-temperature creep properties were analyzed by collecting and comparing literature data. These experimental results provided important material parameter data and also verified the correctness of the CAE material model through material stretching simulation. This helped to more accurately simulate the deformation and reaction of acrylic glass materials during high-temperature forming, and also provided preliminary verification of the correctness of the CAE model. As to process parameters, this thesis studied the effects of parameters such as clamp type and operating trajectory, cooling time, and unequal width blanking on forming results. Through simulation and analysis, it was concluded that the smaller the gap between clamps, the better the forming situation; while keeping the clamp speed perpendicular to the edge of the plate at all times not only made the residual stress after forming smaller but also had a good effect on thickness forming quality. It was also found that the cooling stage could further release stress, but only above 70°C. As for processes with unequal curvature modeling, using unequal width blanking can effectively improve forming results and is relatively easy to adjust. In respect of optical performance, through collecting relevant optical theories and literature, preliminary analysis was conducted on the correspondence between optical performance such as image distortion and chromatic aberration problems and forming indicators, including the effects of parameters such as thickness distribution, residual stress distribution, and density distribution on optical performance. It was also evaluated that computer-automated detection is currently the best way to measure windshield optical performance. The research content of this thesis can provide reference for future analysis or optimization of related processes.