کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
7214566 1469466 2018 24 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Random field generation of stochastically varying through the thickness permeability of a plain woven fabric
ترجمه فارسی عنوان
تولید میدان تصادفی از لحاظ استقبال از طریق نفوذپذیری ضخامت یک پارچه بافته ساده
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی (عمومی)
چکیده انگلیسی
In the Vacuum Assisted Resin Transfer Molding (VARTM) process to manufacture composites, woven or stitched fabrics are stacked on top of a tool surface and resin is introduced into this porous network by drawing a vacuum. For large parts, to reduce the time for filling, highly permeable distribution media (DM) is placed on top of the fabric layers to accelerate the in-plane filling process. Many factors such as the manufacturing process, handling, variation in fabric manufacturing and placement of fabric cause heterogeneity in the permeability of fibrous materials. Due to the presence of the DM, the heterogeneous through the thickness permeability (Kpin) of a fabric can dramatically affect the flow of resin and cause air pockets or voids which are mechanical flaws resulting in the rejection of the composite as scrap. Statistical characterization of Kpin is crucial for understanding the (i) effect of heterogeneity in Kpin and its interaction with DM permeability and void formation and (ii) for generating the field of random numbers (Kpin), which can be used for simulations to predict resin flow and void formation for such materials that exhibit stochastic variability. The novelty of this study is that the observed random field (Kpin) is generated for numerical simulation through statistical analysis. First, in this study, the heterogeneity in Kpin was statistically characterized by spatial correlation with Moran's I index and semi-variogram. Then the random field of Kpin was generated by transforming the normal numbers from Karhunen-Loève (KL) expansion to gamma numbers. A numerical flow simulation of the VARTM process with the generated random fields was performed using Monte Carlo method for three types of Distribution Media (DM). The outcome is compared with experimental results and to simulation results that used experimentally determined Kpin data as an input.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Composites Science and Technology - Volume 159, 3 May 2018, Pages 199-207
نویسندگان
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