Demeng Che

Machining of Carbon Fiber Reinforced Plastics/Polymers: A Literature Review

Carbon fiber reinforced plastics/polymers (CFRPs) offer excellent mechanical properties that lead to enhanced functional performance and, in turn, wide applications in numerous industrial fields. Post machining of CFRPs is an essential procedure that assures that the manufactured components meet their dimensional tolerances, surface quality and other functional requirements, which is currently considered an extremely difficult process due to the highly nonlinear, inhomogeneous, and abrasive nature of CFRPs. In this paper, a comprehensive literature review on machining of CFRPs is given with a focus on five main issues including conventional and unconventional hybrid processes for CFRP machining, cutting theories and thermal/mechanical response studies, numerical simulations, tool performance and tooling techniques, and economic impacts of CFRP machining. Given the similarities in the experimental and theoretical studies related to the machining of glass fiber reinforced polymers (GFRPs) and other FRPs parallel insights are drawn to CFRP machining to offer additional understanding of on-going and promising attempts in CFRP machining.

Issues in Polycrystalline Diamond Compact Cutter–Rock Interaction From a Metal Machining Point of View—Part I: Temperature, Stresses, and Forces

This paper provides a comprehensive review of the literature that deals with issues surrounding the polycrystalline diamond compact (PDC) cutter–rock interface during rock cutting/drilling processes. The paper is separated into two parts addressing eight significant issues: Part I deals with fundamental issues associated with temperature/stress distribution and loading force prediction, while part II focuses on issues related to PDC cutter/bit performance, wear and other failure phenomena, rock removal mechanism and cutting theory, rock properties, and numerical modeling of cutter–rock interaction. Experimental, analytical, and numerical methods are included into the investigation of the abovementioned eight issues. Relevant concepts from metal cutting, micromachining, and other machining processes are also introduced to provide important insights and draw parallels between these interrelated fields. [DOI: 10.1115/1.4007468]

Issues in Polycrystalline Diamond Compact Cutter–Rock Interaction From a Metal Machining Point of View—Part II: Bit Performance and Rock Cutting Mechanics

In Part I of this paper, the issues related to temperature, stress and force were reviewed and parallels were drawn between both metal machining and rock cutting. Part II discusses the issues more directly related to polycrystalline diamond compact (PDC) bit performance and rock mechanics. However, relevant issues in various metal cutting processes will continue to be presented to clarify the gaps and similarities between these two classes of processes. [DOI: 10.1115/1.4007623]

FInite element study on chip formation and force response in two-dimensional orthogonal cutting of rock

The understanding of the rock-cutter interaction is essential for efficient rock cutting/drilling performed with polycrystalline diamond compact (PDC) cutters in petroleum engineering and gas exploration. Finite element modeling of the rock cutting process still remains a challenge due to the complex material properties of rock, rock fracture and chip formation phenomena and large force oscillations during the dominant brittle cutting mode. A finite element study was conducted to investigate the chip formation and force responses in two-dimensional orthogonal cutting of rock. The Drucker-Prager model that incorporates a simple shear strain failure criterion was exploited to simulate the interactions between the rock and the cutter. A fully instrumented rock cutting testbed was developed to enable the measurements of the three orthogonal force components and of the uni-axial acceleration in the cutting direction along rectilinear tool-paths to evaluate the simulation results. The chip formation phenomena and force response predictions derived by the FEM simulations were in good agreement with the experimental tests.Copyright

Rock Cutter Interactions in Linear Rock Cutting

Polycrystalline diamond compact (PDC) cutter, as a major cutting tool, has been widely applied in oil and gas drilling processes. The understanding of the complex interactions at the rock and cutter interfaces are essential for the advancement of future drilling technologies, yet, these interactions are still not fully understood. Linear cutting of rock, among all the testing methods, avoids the geometric and process complexities and offer the most straightforward way to reveal the intrinsic mechanisms of rock cutting. Therefore, this paper presents an experimental study of the cutter’s cutting performance and the rock’s failure behaviors on a newly developed linear rock cutting facility. A series of rock cutting tests were designed and performed. The acquired experimental data was analyzed to investigate the influences of process parameter and the rock’s mechanical properties on chip formation and force responses.Copyright

Finite element study of the cutting mechanics of the three dimensional rock turning process

The unceasing improvements of polycrystalline diamond compact (PDC) cutters have pushed the limits of tool life and cutting efficiency in the oil and gas drilling industry. However, the still limited understanding of the cutting mechanics involved in rock cutting/drilling processes leads to unsatisfactory performance in the drilling of hard/abrasive rock formations. The Finite Element Method (FEM) holds the promise to advance the in-depth understanding of the interactions between rock and cutters. This paper presents a finite element (FE) model of three-dimensional face turning of rock representing one of the most frequent testing methods in the PDC cutter industry. The pressure-dependent Drucker-Prager plastic model with a plastic damage law was utilized to describe the elastic-plastic failure behavior of rock. A newly developed face turning testbed was introduced and utilized to provide experimental results for the calibration and validation of the formulated FE model. Force responses were compared between simulations and experiments. The relationship between process parameters and force responses and the mechanics of the process were discussed and a close correlation between numerical and experimental results was shown.Copyright

Polycrystalline diamond turning of rock

Polycrystalline Diamond Compact (PDC) cutters, as the most commonly used inserts for rock cutting/drilling processes, are drawing increased attentions in manufacturing and petroleum engineering driven by the necessity to elevate cutter and process performance. The knowledge of the force response of single PDC cutters under various cutting conditions is an essential prerequisite for achieving this goal. In this paper, an analytical model is derived by extending Nishimatsu’s two-dimensional orthogonal cutting theory for rock cutting to the three-dimensional quasi-orthogonal case. A rock turning testbed that uses single PDC cutters is developed on a CNC turning center for measuring both thermal and mechanical responses at the rock-cutter interface in real-time. The developed testbed is used to perform the experimental validation of a newly proposed force prediction model.© 2013 ASME

Design and Analysis of Helical Needle Tip Grinding Process

A generalized helical needle tip geometry model, which can describe many typical needle tip geometries, including conical, bevel, blunt and helical shapes with proper geometric parameters, is presented based on analogy to the helical point drill geometry. The generality of this model offers a general way for manufacturing various needle tip geometries. A mathematical model of the helical needle tip geometry is provided along with the formulation of the kinematic model of the tip grinding process. The control strategy on a 5-axis grinding machine system is also developed to implement the designed kinematic model. The needle tip’s motions in the grinding process are simulated to characterize the effects of grinding parameters on needle tip properties and to predict the trajectory of the needle tip point during the grinding process. Finally, several types of needle geometries have been manufactured by the developed grinding process to verify the newly formulated models.Copyright