有限元素法分析纏繞與疊貼工藝製造之碳纖維複材管件的機械性質差異

Abstract

本研究主要在探討纖維纏繞此製造工藝對管件產品機械性質或破壞增長的影響，其被認為是製造複合材料軸對稱零件，例如壓力容器、管件等最有效的技術。然而一些研究論文指出是其中來回交織的纖維層所產生的上下交叉處會造成纖維層之間的機械性質或力學行為與單純疊層理論的纖維層不同，且無法利用市面上現有套裝軟體裡疊層理論產生的二維簡化模型來得知其差異，因此在生產管件產品時，無法選擇出較合適的製造工藝來進行製造。因此本研究將以壓力容器扣除圓蓋結構之複合材料管件為首要分析目標，利用上述兩種製造工藝分別製造出相同參數的管件並比較其差異，藉以分析出纏繞因素所造成之影響，而後並進一步透過完成纏繞模型壓縮實驗來驗證纏繞模型與模擬的可行性。

首先，本研究先透過 MATLAB 撰寫管件不同尺度之纏繞與疊貼 3D 模型，而後將其匯入有限元素軟體 Marc Mentat 進行徑向壓縮分析以探討兩種工藝結構可能存在的差異。而本文發現的第一點為機械性質的差異，在管件半徑尺寸放大的模型實驗，纏繞模型明顯的比疊貼模型更硬。第二點則是達到壓縮強度的形變，因為纏繞結構中的纖維層交疊起伏，不管是哪一個尺寸大小模型的壓縮試驗，纖維纏繞的模型都較快的達到壓縮強度並導致破壞，以上結果都可能是兩種不同工藝製造時可能產生的機械性質差異。

而本研究除了建立了不同尺度的疊貼與纏繞模型並從模擬中探討兩種工藝結構可能存在的差異，也進一步透過完成纏繞模型壓縮實驗來驗證纏繞模型與模擬的可行性。而在實驗與模擬試驗的結果比較下，本研究所建立的模擬模型在斷裂前與實驗的機械性質百分比誤差大約為 6% 以內，因此能推測本文的分析算是有效的方法。而在破壞預測的驗證上，在真實試驗中驗證了模擬中纖維會先從管件上下部分先開始斷裂的結果，且在破壞的位移上，本研究觀察到實驗的模型斷裂的位移則與本研究預測其達到壓縮強度的破壞位移接近。

This study mainly explores the impact of the filament winding manufacturing pro cess on the mechanical properties or damage growth of pipe fittings. It is considered to be the most effective technology for manufacturing composite axisymmetric parts, such as pressure vessels, pipe fittings, etc.However, some research papers point out that the upper and lower intersections caused by the back-and-forth interwoven fiber layers will cause the mechanical properties or mechanical behaviors between the fiber layers to be differ ent from those of the fiber layers in the simple lamination theory, And it is impossible to use the two-dimensional simplified model generated by the stacking theory in the existing software packages on the market to know the difference. As a result, when producing pipe fittings, it is impossible to select a more suitable manufacturing process for manu facturing.Therefore, this study will take the composite pipe fittings of the pressure vessel minus the dome structure as the primary analysis target. The above two manufacturing processes are used to manufacture pipe fittings with the same parameters and comparethe differences, so as to analyze the impact of the winding factor, and then combine The feasibility of the winding model and simulation was further verified by completing the winding model compression experiment. First, this study first used MATLAB to write 3D models of winding and prepreg of different scales of pipe, and then imported them into the finite element software Marc Mentat to conduct radial compression analysis to explore the possible differences between the two process structures. the first point discovered in this article is the difference in stiffness. In the model experiment of enlarging the radius of the pipe, the winding model is obviously harder than the prepreg model. The second point is the deformation that reaches the compressive strength. Because the fiber layers in the winding structure overlap and undulate, no matter which size model is tested in the compression test, the winding model reaches the compressive strength faster and causes damage. The above results It may be due to the difference in mechanical properties that may occur during the manufacturing of two different processes. In addition to establishing prepreg and winding models of different scales and explor ing the possible differences between the two process structures through simulation, this study also further verified the feasibility of the winding model and simulation by com pleting a compression experiment on the winding model. Comparing the results of experiments and simulation tests, the stiffness percentage error between the simulation model established in this study and the experiment before fracture is approximately within 6%. Therefore, it can be inferred that the analysis in this article is an effective method. In terms of verification of damage prediction, real tests have verified that the fibers in the simulation will break first from the upper and lower parts of the pipe. In terms of damage displacement, this study observed that the experimental model fracture displacement is consistent with this study, and the predicted failure displacement to reach compressive strength is close to that.