Using finite element software developed for metal cutting by Third Wave Systems we investigate the forces involved in chatter, a self-sustained oscillation of the cutting tool. The phenomena is decomposed into a vibrating tool cutting a flat surface work piece, and motionless tool cutting a work piece with a wavy surface. While cutting the wavy surface, the shearplane was seen to oscillate in a...

Biomass utilization for bio-energy, bio-fuels or bio-based products requires reduction of the material size within specific ranges depending on feedstock specie, handling and further processing / conversion processes. Biomass size reduction is a mechanical treatment process that refers to either cutting or comminuting processes that significantly change the particles size, shape and bulk densit...

We consider a one-dimensional cutting stock problem (CSP) in which the stock widths are not used to fulfill the order but kept for use in the future for the industrial-use paper production. We present a new model based on the flexible stock allocation and trim loss control to determine the production quantity. We evaluate our approach using a real data and show that we are able to solve industr...

The random k-SAT model is the most important and well-studied distribution over k-SAT instances. It is closely connected to statistical physics and is a benchmark for satisfiability algorithms. We show that when k = Θ(log n), any Cutting Planes refutation for random k-SAT requires exponential size in the interesting regime where the number of clauses guarantees that the formula is unsatisfiable...

INTRODUCTION The purpose of this study was to evaluate the morphologic surface of gutta-percha cones after cutting with different methods. MATERIALS AND METHODS The apical 3 millimeters of forty standardized, gutta-percha cones size 40 were cut off using scissors or a scalpel against a glass slab. The samples were then examined under scanning electron microscopy (SEM) for topographic deformit...

Chatter suppression is essential for achieving high precision and surface quality in machining processes. In this paper, a control strategy is presented for chatter suppression in cutting process in the presence of tool wear and parameter uncertainties. A single-degree-of-freedom model of a turning process in the orthogonal cutting configuration is used to set up the nonlinear delay differentia...

Address correspondence to Lijie Ci, [email protected]; Pulickel M. Ajayan, [email protected] ABSTRACT Rapid progress in graphene-based applications is calling for new processing techniques for creating graphene components with different shapes, sizes, and edge structures. Here we report a controlled cutting process for graphene sheets, using nickel nanoparticles as a knife that cuts with nanos...