Effect of tip profile on cutting processability of a trapezoidal cutting blade indented to an aluminum sheet

Abstract

This paper is an investigation of detaching phenomena of a trapezoidal cutting blade on a wedged surface of a thin work sheet. To study critical conditions for cutting off an aluminum sheet, the wedged profile of the work sheet was experimentally studied by varying the tip thickness of the trapezoidal cutting blade, which simulated a crushed bevel blade. To analyze the detached condition and separation force of the wedged sheet, an elastoplastic finite element program was used to analyze wedge indentation to the work sheet. The following results were obtained: (i) the deformation of the wedged sheet can be classified in four patterns; (ii) the critical condition for cutting off the work sheet depends on the ratio of tip thickness by sheet thickness w/t; (iii) the separation of the work sheet occurred statistically for w/t = 0.13 ∼ 0.28; and (iv) the separation line force can be used to explain the necking mode and the detached condition.

Effect of Underlay Rigidity on Cutting Characteristic of Aluminum Foil during Wedge Shearing Process

“…From this figure, it is evident that the Young's modulus affects the load response at the first stage (f <f max ). When E r >0.12, the load response is almost same as that of the hard underlay on which the worksheet was successfully separated at c/t s = 0.9~1.0 (6)(7)(8) . This means that Young's modulus is not so sensitive factor for cutting processability when the PS sheet or the PC sheet is considered as the underlay.…”

“…In that study, a couple of separation modes were estimated using the ratio of blade tip thickness w and the worksheet thickness t. In case of w/t<0.23, the second mode necking occurred and the string-like burrs were generated beneath the blade tip. In addition, Chaijit et al (8) have investigated the cutting processability of trapezoidal blade on the aluminum worksheet of 0.4mm for w/t>0.23. The separation limit of worksheet was confirmed as exceeded to w/t=0.28.…”

“…When w/t>0.3, the wedge surface was detached from the deformed worksheet and the blade tip mainly pushed the worksheet in an upsetting mode without separation. These researches (6)(7) (8) were based on a hard counter plate without any flexible underlay.…”

Effect of Underlay Stiffness on Cutting Profile of Polycarbonate Sheet during Wedge Indentation Process

“…In that study, a couple of separation modes were estimated using the ratio of blade tip thickness w and the worksheet thickness t. In case of w/t<0.23, the second mode necking occurred and the string-like burrs were generated beneath the blade tip. Chaijit et al (8) have investigated the cutting processability of a trapezoidal blade on the aluminum worksheet of 0.4mm for w/t>0.23. The separation limit of worksheet was confirmed as exceeded to w/t=0.28 and when w/t >0.3, the wedge surface was detached from the deformed worksheet and the blade tip mainly pushed the worksheet in an upsetting mode without separation.…”

“…The separation limit of worksheet was confirmed as exceeded to w/t=0.28 and when w/t >0.3, the wedge surface was detached from the deformed worksheet and the blade tip mainly pushed the worksheet in an upsetting mode without separation. Several research works (6)(7) (8) were based on a hard counter plate without any flexible underlay. In that reports, a cutting mechanism of trapezoidal blade was mainly discussed with respect to w/t <0.3 (t=0.4mm), whereas the thinner sheets, that is less than 15μm thickness, are often required to cut off in the pattern die-cutting of resin sheets or thin metal sheets.…”