Laser beam machining (LBM) is one of the most widely used thermal energy based non-contact type advance machining process which can be applied for almost whole range of materials. Laser beam is focussed for melting and vaporizing the unwanted material from the parent material. It is suitable for geometrically complex profile cutting and making miniature holes in sheetmetal. Among various type of lasers used for machining in industries, CO2 and Nd:YAG lasers are most established. In recent years, researchers have explored a number of ways to improve the LBM process performance by analysing the different factors that affect the quality characteristics. The experimental and theoretical studies show that process performance can be improved considerably by proper selection of laser parameters, material parameters and operating parameters. This paper reviews the research work carried out so far in the area of LBM of different materials and shapes. It reports about the experimental and theoretical studies of LBM to improve the process performance. Several modelling and optimization techniques for the determination of optimum laser beam cutting condition have been critically examined. The last part of this paper discusses the LBM developments and outlines the trend for future research.

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Laser beam machining—A review

Delamination formation, evaluation and suppression during drilling of composite laminates: A review

Fiber-reinforced polymer (FRP) composites are extensively used in advanced concrete technology given their superiority over traditional steel reinforcements. These materials possess high strength capacity and corrosion resistance and can be employed as the main reinforcements in combination with adhesives and anchorages to strengthen reinforced concrete (RC) beam members. RC beams are designed to provide resistance against flexure , shear, torsion, fatigue, impact, and blast loading. The strength and ductility of RC beams can be improved via FRP strengthening techniques with a combination of fibers. The overall strength of FRP composites in RC beams is controlled by fiber type , configuration, and materials and strengthening technique. This review focuses on the characteristics and behaviors of FRP-strengthened RC beams under various loading conditions. It also presents the typical FRP composites with the properties, features, and applications. This review demonstrates that FRP composites can be used to recover the strength of damaged and corroded beams and exhibit good durability and insulation performance. It also provides a straightforward perspective of strengthening and retrofitting techniques for RC beams using FRP composites.

Strengthening of reinforced concrete beams by using fiber-reinforced polymer composites: A review

Monitoring and processing signal applied in machining processes – A review

Carbon fibre reinforced polymer (CFRP) composites have excellent specific mechanical properties, these materials are therefore widely used in high-tech industries like the automobile and aerospace sectors. The mechanical machining of CFRP composites is often necessary to meet dimensional or assembly-related requirements; however, the machining of these materials is difficult. In an attempt to explore this issue, the main objective of the present paper is to review those advanced cutting tools and technologies that are used for drilling carbon fibre reinforced polymer composites. In this context, this paper gives a detailed review and discussion of the following: (i) the machinability of CFRP including chip removal mechanisms, cutting force, tool wear, surface roughness, delamination and the characteristics of uncut fibres; (ii) cutting tool requirements for CFRP machining; and (iii) recent industrial solutions: advanced edge geometries of cutting tools, coatings and technologies. In conclusion, it can be stated that advanced geometry cutting tools are often necessary in order to effectively and appropriately machine required quality features when working with CFRP composites.

Advanced cutting tools and technologies for drilling carbon fibre reinforced polymer (CFRP) composites: A review

A new method to reduce delaminations during drilling of FRP laminates by feed rate control

In process monitoring of cutting temperature during the drilling of FRP laminate

Cutting force and energy are often used as parameters for monitoring the stone cutting process. Empirical models are required to guide the selection of cutting conditions. In this paper, the effect of cutting conditions on cutting force and energy are reviewed. The effects of cutting conditions on cutting force and cutting energy are related to the shape of the idealized chip thickness. The empirical models developed in this paper can be used to predict the variation of the cutting energy. Therefore, the models can be used to guide the selection of cutting conditions. The chip generation and removal process has been quantified with the intention of assisting both the toolmaker and the stonemason in optimising the tool composition and cutting process parameters, respectively.

Force and specific energy in stone cutting by diamond mill

Stone machining by diamond tool is a widespread process to manufacture both standard products, such as tiles, slabs, kerbs, and so on, and design shapes. Cutting force and energy may be used to monitor stone machining. Empirical models are required to guide the selection of cutting conditions. In this paper, the effects of cutting conditions on cutting force and cutting energy are related to the shape of the idealized chip thickness. These effects are put into relationship with the diamond tool wear too. The empirical models developed in this paper can be used to predict the variation of the cutting energy. Therefore these models can be used to guide the selection of cutting conditions and to predict when it is needed to change the tool. The chip generation and removal process has been quantified with the intention of assisting both the toolmaker and the stonemason in optimizing the tool composition and cutting process parameters, respectively.

Cutting force and diamond tool wear in stone machining

The present work shows a study on cutting of stone by diamond tool. The diamond grits on the tool surface remove material through the scratching and the cracking of the stone volume. This work reports a kinematics analysis between a single grit of a diamond tool and the stone volume. In previous works, a mathematical relationship of the chipping geometry, due to a single grit, with machining and tool parameters has been derived. This work aims to measure the cutting force due to a single tool grit for different machining conditions. In particular, the machining conditions that are most interesting by an industrial point of view have been investigated. The stone cutting force has been measured by a Kistler 9257 BA piezoelectric platform dynamometer. The outputs of the dynamometer were fed into an A/D converter and sampled at high frequency by a PC. Then, the signals recorded by the PC were filtered by Matlab software at a low frequency. The collected data have been put into relationship with machining and tool parameters.

Sandro Turchetta

Papers

A new method to reduce delaminations during drilling of FRP laminates by feed rate control

In process monitoring of cutting temperature during the drilling of FRP laminate

Force and specific energy in stone cutting by diamond mill

Cutting force and diamond tool wear in stone machining

Cutting force on a diamond grit in stone machining