Aerospace composites mechanical damage prediction through multi-scale modelling

通过多尺度建模进行航空航天复合材料机械损伤预测

• 批准号: RGPIN-2016-06412
• 负责人: Lévesque, Martin
• 金额: $ 4.23万
• 依托单位: École Polytechnique de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=690748
• 关键词: Aerospace; composites; mechanical; damage; prediction

The replacement of metallic aerospace parts by the introduction of composites in the 1960's offered the promises of lighter aircraft. Lighter aircraft consume less fuel, which provides a competitive advantage to aircraft manufacturers, and reduce polluting emanations, which is essential to ensure Earth's sustainability. Yet, weight savings in Canadian aircraft range from 0 to 5%, whereas senior aerospace composites experts believe that it could safely be around 15%, and beyond with new composites. Prohibitively expensive certification costs and over-conservative safety factors contribute to this poor performance. This situation must absolutely be remedied to maintain Canada's competitiveness in aerospace.***Accurate composites predictive damage models could significantly decrease the weight of composite parts, since: i) some certification tests could be replaced by predictions, which would accelerate the introduction newer materials of improved performance and ii) accurate models will lead to lower safety factors, and hence, to lighter aircraft. The World Wide Failure Exercise on composites revealed that current models cannot predict composite failure within reasonable accuracy for every load case. Composites damage is a complex process initiated by sub-micron cracks that propagate through the hierarchy of scales. Classical continuum mechanic is ill-suited for handling these discontinuities. ***The proposed research program aims at developing a multi-scale framework for predicting composites failure by simultaneously investigating: i) experimental methods for identifying relevant material parameters, ii) models for predicting composites damage initiation and propagation and iii) numerical strategies for delivering efficient composites damage predictions. The program relies on Peridynamics, which is a relatively new formulation for continuum mechanics that eludes most of the classical approaches' shortcomings. ***The research will be carried out by 4 PhD students and 1 post-doctoral fellow, supported by 13 undergraduate students and 1 research associate. Most graduate students will be co-supervised by professors of complementary expertise (experimental, theoretical and numerical). Every PhD student will perform a short-time (2-3 weeks) internship with well-known international experts, as well as a four-month internship in an aerospace company as part of a larger training program aiming at improving the aerospace industry readinyness level of graduate students.***This program should trigger the essential paradigm shift for properly addressing composites damage prediction, and hence reap the full weight reduction potential composites offer. The methodology is tailored for the aerospace industry to accelerate its transfer with the next generation of experts that will be specifically trained for that objective throughout the program. *** *** *** **

20 世纪 60 年代，复合材料的引入取代了金属航空航天部件，为制造更轻的飞机带来了希望。较轻的飞机消耗的燃料较少，这为飞机制造商提供了竞争优势，并减少污染排放，这对于确保地球的可持续性至关重要。然而，加拿大飞机的重量减轻了 0% 到 5%，而高级航空航天复合材料专家认为，使用新型复合材料可以安全地减轻 15% 左右，甚至更多。昂贵的认证成本和过于保守的安全因素导致了这种糟糕的性能。为了保持加拿大在航空航天领域的竞争力，这种情况必须得到纠正。***准确的复合材料预测损伤模型可以显着减轻复合材料零件的重量，因为：i）一些认证测试可以用预测代替，这将加速新材料的引入改进的性能和 ii) 准确的模型将导致安全系数降低，从而使飞机变得更轻。全球复合材料失效演习表明，当前模型无法以合理的精度预测每种载荷情况下的复合材料失效。复合材料损伤是一个复杂的过程，由亚微米裂纹引发，裂纹通过尺度层次传播。经典的连续介质力学不适合处理这些不连续性。 ***拟议的研究计划旨在通过同时研究以下内容来开发预测复合材料失效的多尺度框架：i）用于识别相关材料参数的实验方法，ii）用于预测复合材料损伤萌生和传播的模型以及iii）用于交付的数值策略有效的复合材料损伤预测。该程序依赖于近场动力学，这是一种相对较新的连续介质力学公式，克服了大多数经典方法的缺点。 ***该研究将由 4 名博士生和 1 名博士后研究员进行，并得到 13 名本科生和 1 名研究员的支持。大多数研究生将由具有互补专业知识（实验、理论和数值）的教授共同指导。每位博士生将与国际知名专家进行短期（2-3周）实习，并在一家航空航天公司进行为期四个月的实习，作为旨在提高航空航天业准备水平的更大培训计划的一部分***该计划应该引发正确解决复合材料损伤预测的基本范式转变，从而充分发挥复合材料减重的潜力。该方法是为航空航天业量身定制的，以加速下一代专家的转移，这些专家将在整个计划中为此目标接受专门培训。 *** *** *** **