Aggogeri Francesco, Borboni Alberto, Merlo Angelo, Pellegrini Nicola, Ricatto Raffaele
Department of Mechanical and Industrial Engineering, University of Brescia, via Branze, 38, 25123 Brescia, Italy.
CE.S.I Centro Studi Industriali, via Tintoretto, 10, 20093 Cologno Monzese, Italy.
Materials (Basel). 2017 Mar 15;10(3):297. doi: 10.3390/ma10030297.
The dynamic behaviour of a machine tool (MT) directly influences the machining performance. The adoption of lightweight structures may reduce the effects of undesired vibrations and increase the workpiece quality. This paper aims to present and compare a set of hybrid materials that may be excellent candidates to fabricate the MT moving parts. The selected materials have high dynamic characteristics and capacity to dampen mechanical vibrations. In this way, starting from the kinematic model of a milling machine, this study evaluates a number of prototypes made of Al foam sandwiches (AFS), Al corrugated sandwiches (ACS) and composite materials reinforced by carbon fibres (CFRP). These prototypes represented the -axis ram of a commercial milling machine. The static and dynamical properties have been analysed by using both finite element (FE) simulations and experimental tests. The obtained results show that the proposed structures may be a valid alternative to the conventional materials of MT moving parts, increasing machining performance. In particular, the AFS prototype highlighted a damping ratio that is 20 times greater than a conventional ram (e.g., steel). Its application is particularly suitable to minimize unwanted oscillations during high-speed finishing operations. The results also show that the CFRP structure guarantees high stiffness with a weight reduced by 48.5%, suggesting effective applications in roughing operations, saving MT energy consumption. The ACS structure has a good trade-off between stiffness and damping and may represent a further alternative, if correctly evaluated.
机床（MT）的动态行为直接影响加工性能。采用轻质结构可以减少不良振动的影响并提高工件质量。本文旨在介绍和比较一组可能是制造机床运动部件的优秀候选材料的混合材料。所选材料具有高动态特性和抑制机械振动的能力。通过这种方式，从铣床的运动学模型出发，本研究评估了一些由泡沫铝三明治（AFS）、波纹铝三明治（ACS）和碳纤维增强复合材料（CFRP）制成的原型。这些原型代表了一台商用铣床的X轴滑枕。通过使用有限元（FE）模拟和实验测试对静态和动态特性进行了分析。获得的结果表明，所提出的结构可能是机床运动部件传统材料的有效替代品，可提高加工性能。特别是，AFS原型突出显示出阻尼比是传统滑枕（例如钢）的20倍。其应用特别适合在高速精加工操作期间最小化不必要的振动。结果还表明，CFRP结构保证了高刚度，重量减轻了48.5%，表明在粗加工操作中有有效的应用，节省机床能耗。ACS结构在刚度和阻尼之间有很好的权衡，如果评估正确，可能是另一种选择。
