Effect of Machining Cusps on the Stress Concentration Factor on Curved Surface

Simon Barrans, Md Shams E. Tabriz

Research output: Contribution to journalArticle

Abstract

Recently multi-axis machining technology has improved significantly. It has become a widely accepted method of manufacturing components with complex, free form surfaces. Solid billet materials with negligible internal defects are used in this process. This provides increased durability and fatigue life over equivalent cast components. However, multi-axis machining using ball nose cutting tools leaves cusps as machining marks. The combination of tool size and step-over generates cusps with different depths and widths. Even though the cusps add extra material on top of the nominal surface, Finite Element Analysis (FEA) shows the maximum stress generated within the cusps is greater than that predicted from the cusp-free geometry. These stress concentrations generated by cusps can reduce the fatigue life and durability of a machined component. This paper reports FEA results; simulating the effect of cusps on surfaces with a range of curvatures for a fixed tool size and six different cusps depth. The FEA results show that the stress concentrations due to surface curvature and cusps can be determined independently and then multiplied together to give the combined stress concentration factor. The results of this analysis will allow designers to specify a maximum machining cusp depth on a curved surface.

Original languageEnglish
Pages (from-to)552-557
Number of pages6
JournalInternational Journal of Mechanical Engineering and Robotics Research
Volume7
Issue number5
DOIs
Publication statusPublished - 1 Sep 2018

Fingerprint

Stress concentration
Machining
Finite element method
Durability
Fatigue of materials
Cutting tools
Defects
Geometry

Cite this

@article{bcb913849f4648eb98d7b113a1a66862,
title = "Effect of Machining Cusps on the Stress Concentration Factor on Curved Surface",
abstract = "Recently multi-axis machining technology has improved significantly. It has become a widely accepted method of manufacturing components with complex, free form surfaces. Solid billet materials with negligible internal defects are used in this process. This provides increased durability and fatigue life over equivalent cast components. However, multi-axis machining using ball nose cutting tools leaves cusps as machining marks. The combination of tool size and step-over generates cusps with different depths and widths. Even though the cusps add extra material on top of the nominal surface, Finite Element Analysis (FEA) shows the maximum stress generated within the cusps is greater than that predicted from the cusp-free geometry. These stress concentrations generated by cusps can reduce the fatigue life and durability of a machined component. This paper reports FEA results; simulating the effect of cusps on surfaces with a range of curvatures for a fixed tool size and six different cusps depth. The FEA results show that the stress concentrations due to surface curvature and cusps can be determined independently and then multiplied together to give the combined stress concentration factor. The results of this analysis will allow designers to specify a maximum machining cusp depth on a curved surface.",
keywords = "Cusps, Finite element analysis, Machining marks, Multi-axis machining, Stress concentration, Surface curvature",
author = "Simon Barrans and Tabriz, {Md Shams E.}",
year = "2018",
month = "9",
day = "1",
doi = "10.18178/ijmerr.7.5.552-557",
language = "English",
volume = "7",
pages = "552--557",
journal = "International Journal of Mechanical Engineering and Robotics Research",
issn = "2278-0149",
publisher = "International Journal of Mechanical Engineering and Robotics Research",
number = "5",

}

Effect of Machining Cusps on the Stress Concentration Factor on Curved Surface. / Barrans, Simon; Tabriz, Md Shams E.

In: International Journal of Mechanical Engineering and Robotics Research, Vol. 7, No. 5, 01.09.2018, p. 552-557.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Effect of Machining Cusps on the Stress Concentration Factor on Curved Surface

AU - Barrans, Simon

AU - Tabriz, Md Shams E.

PY - 2018/9/1

Y1 - 2018/9/1

N2 - Recently multi-axis machining technology has improved significantly. It has become a widely accepted method of manufacturing components with complex, free form surfaces. Solid billet materials with negligible internal defects are used in this process. This provides increased durability and fatigue life over equivalent cast components. However, multi-axis machining using ball nose cutting tools leaves cusps as machining marks. The combination of tool size and step-over generates cusps with different depths and widths. Even though the cusps add extra material on top of the nominal surface, Finite Element Analysis (FEA) shows the maximum stress generated within the cusps is greater than that predicted from the cusp-free geometry. These stress concentrations generated by cusps can reduce the fatigue life and durability of a machined component. This paper reports FEA results; simulating the effect of cusps on surfaces with a range of curvatures for a fixed tool size and six different cusps depth. The FEA results show that the stress concentrations due to surface curvature and cusps can be determined independently and then multiplied together to give the combined stress concentration factor. The results of this analysis will allow designers to specify a maximum machining cusp depth on a curved surface.

AB - Recently multi-axis machining technology has improved significantly. It has become a widely accepted method of manufacturing components with complex, free form surfaces. Solid billet materials with negligible internal defects are used in this process. This provides increased durability and fatigue life over equivalent cast components. However, multi-axis machining using ball nose cutting tools leaves cusps as machining marks. The combination of tool size and step-over generates cusps with different depths and widths. Even though the cusps add extra material on top of the nominal surface, Finite Element Analysis (FEA) shows the maximum stress generated within the cusps is greater than that predicted from the cusp-free geometry. These stress concentrations generated by cusps can reduce the fatigue life and durability of a machined component. This paper reports FEA results; simulating the effect of cusps on surfaces with a range of curvatures for a fixed tool size and six different cusps depth. The FEA results show that the stress concentrations due to surface curvature and cusps can be determined independently and then multiplied together to give the combined stress concentration factor. The results of this analysis will allow designers to specify a maximum machining cusp depth on a curved surface.

KW - Cusps

KW - Finite element analysis

KW - Machining marks

KW - Multi-axis machining

KW - Stress concentration

KW - Surface curvature

UR - http://www.scopus.com/inward/record.url?scp=85052923898&partnerID=8YFLogxK

U2 - 10.18178/ijmerr.7.5.552-557

DO - 10.18178/ijmerr.7.5.552-557

M3 - Article

VL - 7

SP - 552

EP - 557

JO - International Journal of Mechanical Engineering and Robotics Research

JF - International Journal of Mechanical Engineering and Robotics Research

SN - 2278-0149

IS - 5

ER -