INVESTIGATION OF THERMOELASTIC AND DYNAMIC PHENOMENA FOR IMPROVED DESIGN AND CONTROL OF MANUFACTURING AND TRIBOLOGICAL SYSTEMS

研究热弹性和动态现象以改进制造和摩擦系统的设计和控制

• 批准号: RGPIN-2020-06223
• 负责人: Attia, Mahmoud
• 金额: $ 3.35万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=718266
• 关键词: INVESTIGATION; THERMOELASTIC; DYNAMIC; PHENOMENA; IMPROVED

This proposal deals with high performance machining processes and the prediction of fretting wear under complex excitation. These issues are interrelated, since the integrity of machined surfaces controls its tribological behaviour. Four projects P1 to P4 are proposed: P1-Development of a real-time tool wear prediction, and pre-failure detection system In Phase-1, a novel approach was developed to detect and stop the turning operation before tool chipping (within 20 milliseconds). The objective of the proposed work is to extend this approach to monitoring tool wear level and to detect tool pre-failure in high speed milling of Ti alloys and difficult-to-cut materials, where thermal effects have significant effect. The system should also be operating in the presence of an adaptive control system. Outcome and impact: It is anticipated the proposed system will be unique and can reduce the cost by 20%. P2-Process development for cryogenic deep-hole drilling Building on the success in Phase-1 for turning, the objective is to develop a cryogenic deep hole drilling process, using liquid nitrogen (LiN), overcoming the challenge of injecting LiN in a confined space through a rotating tool. Combining LiN with a minimum quantity lubrication (MQL) jet will be investigated, through CFD modeling to understand the flow characteristics of the dual LiN and MQL jets when supplied through the tool. Comparison between the performance of LiN and supercritical CO2 cryogens will be carried out. Outcome and impact: Compared to flood cooling of Ti6Al4V, it is anticipated that the tool life improvement will be ~ 100% and the environmental impact will be two orders of magnitude. P3-Development of a mixed-regime vibration-assisted drilling (VAD) process for hybrid stacked composites-metal structure The objective is to develop a novel mixed-regime VAD process that superimposes low frequency-high amplitude (LFHA ) and high frequency-low amplitude (HFLA) excitations to explore the possibility of gaining the benefits of both regimes and to allow adaptive control of the process through adjustment of the frequency/amplitude levels and/or the feedrate when drilling FRP/metal stacks. Outcome and impact: From simulation results, it is anticipated that the reduction in forces and temperature will exceed the individual benefits of each regime. As enabling technology, this development will overcome the challenges of robotized machining of stacked structures. P4-Modeling and experimental investigation of fretting wear under random vibration The main objective is to extend the generalized fretting wear theory' proposed by the applicant to predict the damage under random excitation, and to develop a new experimental methodology for the standardization of fretting wear tests under random excitations. Outcome and impact: Preliminary test results showed that conventional sinusoidal excitation testing is non-conservative and could have significant safety and economic implications.

这一建议涉及高性能加工工艺和复杂激励下微动磨损的预测。这些问题是相互关联的，因为加工表面的完整性控制其摩擦学行为。提出了四个项目P1至P4： P1-开发实时刀具磨损预测和故障前检测系统 在第一阶段，开发了一种新的方法来检测和停止刀具崩刃前（20毫秒内）的车削操作。所提出的工作的目的是扩展这种方法来监测刀具磨损水平，并检测在高速铣削钛合金和难切削材料，热效应有显着的效果，刀具预故障。该系统还应在存在自适应控制系统的情况下运行。成果和影响：预计拟议的系统将是独一无二的，可以减少20%的成本。 P2-低温深孔钻削工艺开发 在第一阶段车削成功的基础上，目标是开发一种使用液氮（LiN）的低温深孔钻削工艺，克服通过旋转刀具在有限空间内注入LiN的挑战。将LiN与最小量润滑（MQL）射流相结合进行研究，通过计算流体动力学建模来了解通过工具供应时双LiN和MQL射流的流动特性。将进行LiN和超临界CO2制冷剂之间的性能比较。成果和影响：与Ti6 Al 4V的溢流冷却相比，预计刀具寿命将提高约100%，对环境的影响将是两个数量级。 P3-混合堆叠复合材料-金属结构的混合状态振动辅助钻孔（VAD）工艺的开发 我们的目标是开发一种新的混合制度VAD过程，叠加低频高振幅（LFHA）和高频低振幅（HFLA）的激励，探索获得这两个制度的好处的可能性，并允许自适应控制的过程中，通过调整的频率/振幅水平和/或进给速度时，钻FRP/金属堆。成果和影响：从模拟结果来看，预计力和温度的降低将超过每种制度的单独效益。作为使能技术，这一发展将克服堆叠结构自动化加工的挑战。 P4-随机振动下微动磨损的建模与实验研究 主要目的是扩展申请人提出的广义微动磨损理论来预测随机激励下的损伤，并为随机激励下微动磨损试验的标准化发展一种新的实验方法。成果和影响：初步试验结果表明，传统的正弦激励试验是不保守的，可能有显着的安全和经济的影响。