مقاله انگلیسی رایگان در مورد شکاف مواد فیبرهای پلیمری تقویت شده – اسپرینگر 2018

A major difference between metallic and composite materials is their structure: isotropic for metals and anisotropic for composites. Indeed, components made from composite materials are normally cured to near-net-shape. Machining operations such as slotting, turning, drilling, edge trimming, and grinding are still required to remove excess material to final shape, produce complex contours, and meet product dimensional tolerances as well as quality surface roughness specified in the definition drawing to facilitate component assembly [1, 2]. To describe surface roughness, most research used average roughness parameter Ra [3, 4], some others choose 10-point height roughness Rz [5, 6]. Takeyama et al.[7] preferred maximum peak-to-valley height parameter Ry in order to describe machined carbon fiber reinforced plastic (CFRP) surface roughness. Gara, Wang et al. and Wern[8–10] said that Ry and Rz are better than average roughness parameter Ra and root-mean square height distribution of the profile within the sampling length Rq in quantifying the amount of surface variation in FRP materials. In 1993, Ramulu et al. [11] tried to evaluate the effectiveness of surface roughness parameters in describing the machined surface of CFRP composite: their studies have confirmed them the result of Wang et al. and Wern [9, 10]. They added that no single parameter studies can describe the surface profile measured but a combination of Ry and Rz criteria is better. Focusing on parameters influencing surface roughness, Sheikh Ahmad et al. [12] found that transverse surface roughness does not have clear trends, it is generally higher than the longitudinal surface roughness which increased with an increase in feed rate and a decrease in spindle speed. Gara et al. [13] did not confirm this idea, they said that transverse roughness depends only on tool geometry whatever cutting condition variations when slotting of CFRP material (G803/914) with three burr tools having different geometries. Janardhan [5] said that the longitudinal roughness measurements are conditioned by tool geometry and cutting conditions: results approved by several other researchers [8, 13–17].