A finite element simulation of the spherical mandrelling process of holes with cracks

Maximov, J. T.; Kuzmanov, T.V.; Anchev, A. P.; Ichkova, M.D.

doi:10.1016/j.jmatprotec.2005.08.016

Cited by 20 publications

(8 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The fatigue failure of cyclic loaded structural components is provoked by crack growing in the surface layer [1][2][3]. The fastener holes as natural stress concentrators are a basic factor for the fatigue strength of these components [4,5].…”

Section: Introductionmentioning

confidence: 99%

Modelling of residual stress relaxation around cold expanded holes in carbon steel

Maximov

Duncheva

Mitev

2009

Journal of Constructional Steel Research

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 99%

Modelling of residual stress relaxation around cold expanded holes in carbon steel

Maximov

Duncheva

Mitev

2009

Journal of Constructional Steel Research

View full text Add to dashboard Cite

“…This form of die material failure is determined as thermal fatigue failure. Moreover, all disturbances in the internal structure of the die material [16,17] such as carbide precipitates, point defects and rapid changes in shape and surface, i.e., notches and scratches, are also places of stress concentration. The cyclically changing nature of the external mechanical loads acting on the die in the production cycle causes fatigue processes defined as mechanical fatigue of the material.…”

Section: Working Conditions and Typical Wear Mechanisms Of Forging Diesmentioning

confidence: 99%

Hard Protective Layers on Forging Dies—Development and Applications

Smolik

2021

Coatings

View full text Add to dashboard Cite

The article presents a summary of many years of activities in the area of increasing the durability of forging dies. The results of comprehensive research work on the analysis of the destructive mechanisms of forging dies and the possibility of increasing their durability with the use of modern surface engineering methods are presented. Great possibilities in terms of shaping operational properties of forging dies by producing hybrid layers of the “Nitrided Layer + PVD Coating” (NL + PVD coating) type were confirmed. An analysis of changes in forging dies durability under various operating conditions was performed, i.e., forging—die—forging press—pressures. It has been shown that the variety of parameters of the forging process, including forgings’ geometry and weight, materials, precision, pressures applied, and, what is very important, quality of machines, makes it very difficult to compare the effectiveness of various PVD coating solutions in the process of increasing the durability of forging dies. Hybrid layers of the “NL + PVD coating” type create great possibilities in shaping the operational properties of tools and machine elements. However, in each application a precise diagnosis of the wear mechanism and the design of an individual PVD coating material solution is required.

show abstract

“…Nevertheless, the cold expansion can be carried out by different methods -(1) A solid mandrel with a bulge in or without conjunction with a split sleeve that has parallel walls [1]; (2) A split mandrel [1]; (3) A tapered mandrel used with a mating tapered split sleeve [2]; (4) Spherical mandrelling [5,6,10], where the tool performs a complex motion -the residual stress distribution in qualitative aspect is the same. A feature common to all four methods is that an oversized tool is forced through the hole to produce a local plastic field surrounded by an elastic one.…”

Section: Theoretical Background Of the Researchmentioning

confidence: 99%