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Evaluation of Machinability Indicators in Milling of Thin-Walled Composite Structures

Ciecieląg Krzysztof

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 1

202--212

EN

Composite materials are alternative materials to aluminum and titanium alloys. The wide-spread use of this materials makes it necessary to gain insight into the phenomena occurring in machining processes for thin-walled structures. This paper shows the investigation of the machinability of thin-walled composite materials. The study involved milling glass and carbon reinforced plastics using tools dedicated to the processing of this type of material. Their machinability was determined based on the measured feed force, deformation and surface roughness. In addition, surface analysis was performed by SEM. The results showed that the feed had the greatest impact on the feed force, deformation and surface roughness, followed by cutting speed. Lower values of the measured machinability indicators such as the maximum feed force and roughness were obtained for composites with glass fibers. Lower deformations were induced in the machining of composites with carbon fibers. The study also involved conducting a recurrence analysis in order to select the most appropriate quantifications depending on the technological parameters of milling. It was found that the most appropriate indicators related with the technological parameters for both materials were laminarity and averaged diagonal length.

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Effect of Composite Material Fixing on Hole Accuracy and Defects During Drilling

Ciecieląg Krzysztof

Advances in Science and Technology. Research Journal

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2021

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Vol. 15, no 3

54--65

EN

This study investigates the effect of composite material stiffness on the accuracy of drilled holes and delamination in the drilling process. Two types of composite materials were tested: glass fiber reinforced plastic (GFRP) and carbon fiber reinforced plastic (CFRP). The drilling process was performed using dedicated drill bits. Samples were clamped in a vice of the Avia-VMC 800 HS vertical machining center. Drilling parameters were maintained constant but unsupported element length was changed. The unsupported element length was defined as an unsupported distance between the drilled hole axis and the sample attachment location. The maximum feed force Ff was determined in the experiments. The accuracy of drilled holes was estimated by optical microscopy. Diameters of the drilled holes were measured. Results made it possible to determine the recommended unsupported element length at which the hole dimensions were within the dimensional tolerance. The study showed a clear decrease in the drilled hole quality and a significant increase in the feed force, especially in the area of tool exit from the workpiece. In addition, the number of delaminated fibers increased with unsupported element length was determined in the study.

3

Pultruzja - efektywna metoda wytwarzania półwytworów z tworzyw wzmocnionych włóknami

Krywult B.

Polimery

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2001

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T. 46, nr 10

673-677

PL

W artykule przeglądowym poświęconym charakterystyce pultruzji ciągłego procesu technologicznego wytwarzania prętów, rur i kształtowników z TWW - przedstawiono technologiczny opis tego procesu oraz wymagania materiałowe dotyczące zarówno włókien, i przesycającej je żywicy (żywicznej osnowy). Szczegółowo omówiono wpływ zawartości włókien wzmacniających oraz elastyczności żywicznej osnowy na naprężenia styczne występujące w strukturze otrzymywanych półwytworów z TWW. Podkreślono przy tym trudności związane z wyborem żywicy o odpowiedniej elastyczności i właściwościach cieplnych.

EN

A review with 9 refs. covering a continuous pultrusion process for making GRP rod, pipe, and other shaped sections, specifying the requirements on glass fiber and impregnating (matrix) resin. Tangential stresses occurring in the product are discussed in relation to fiber content and resin elasticity.