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: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=741099
• 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.

这项建议涉及高性能的加工过程和复杂激励下的微动磨损预测。这些问题是相互关联的，因为加工表面的完整性控制着它的摩擦学行为。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切屑前的车削操作(在20毫秒内)。这项工作的目的是将这种方法扩展到监测刀具磨损水平，并在高速铣削钛合金和难切削材料时检测刀具预失效，其中热效应具有显著影响。该系统还应在存在自适应控制系统的情况下运行。结果和影响：预计拟议的系统将是独一无二的，可以降低20%的成本。P2-低温深孔钻探工艺开发在第一阶段车削取得成功的基础上，目标是开发一种使用液氮(LIN)的低温深孔钻探工艺，克服通过旋转工具在受限空间中注入LIN的挑战。将通过CFD建模研究LIN与最小数量润滑(MQL)喷嘴的组合，以了解通过该工具提供的双LIN和MQL喷嘴的流动特性。将对LIN和超临界CO2制冷机的性能进行比较。结果和影响：与Ti6Al4V的洪水冷却相比，预计刀具寿命将提高~100%，对环境的影响将达到两个数量级。P3-针对混杂叠层复合材料-金属结构的混合状态振动辅助钻削(VAD)工艺的开发目标是开发一种新的混合状态VAD工艺，该工艺将低频-高振幅(LFHA)和高频-低振幅(HFLA)激励叠加在一起，以探索获得两种工况的益处的可能性，并允许在钻孔FRP/金属叠层时通过调整频率/振幅水平和/或进给速度来对工艺进行自适应控制。结果和影响：根据模拟结果，预计部队和温度的减少将超过每个制度的单独好处。作为使能技术，这一发展将克服堆叠结构的机器人加工的挑战。P4-随机振动下微动磨损的建模与实验研究主要目的是推广申请人提出的“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。结果和影响：初步测试结果表明，传统的正弦激励测试是非保守的，可能具有显著的安全性和经济性。