IS 18795 : 2024 Metallic Materials - Fatigue Testing - Axial-Strain-Controlled Method (ISO 12106 : 2017, MOD)
NATIONAL FOREWORD
This Indian Standard which was a modified adoption of ISO 12106 : 2017 'Metallic materials - Fatigue testing - Axial-strain-controlled method' issued by the International Organization for Standardization (ISO), was adopted by the Bureau of Indian Standards on the recommendation of Mechanical Testing of Metals Sectional Committee and approval of the Metallurgical Engineering Division Council.
The portions given in dotted underlines are the matters not specified in the corresponding International Standard. A list of technical modifications is given in National Annex C.
Materials and their microstructure may change when subjected to cyclic deformations and their mechanical properties can be significantly altered when compared with that resultant from monotonic deformations, for example, uniaxial stress-strain response. The design of mechanical components subjected to fatigue loadings and cyclic deformations requires, in a number of industrial sectors (that is, nuclear, aerospace, ground vehicles, medical devices, etc), knowledge of the cyclic behaviour of the materials under reversed strain control conditions, referred to as low-cycle fatigue, when cyclic plasticity is present.
In order to ensure reliability and consistency of results from different laboratories, it is necessary to collect all data using test methodologies that comply with a number of key points.
This document concerns both the generation of such strain-controlled fatigue data at room or elevated temperatures at fixed R-ratios (strain) and the presentation of results for fatigue properties, strain-life behaviour and cyclic stress-strain responses of metallic materials determined at an Re-ratio = -1. Since there is a close relationship with strain-controlled, high-temperature testing, there is also a section devoted to creep-fatigue testing methodology.
This document does not address safety or health concerns, should such issues exist, that may be associated with its use or application. The user of this document has the sole responsibility to establish any appropriate safety and health concerns, as well as to determine the applicability of any national or local regulatory limitations regarding the use of this document.
Except the deviations identified in National Annex C, the remaining text of the ISO standard has been approved as suitable for publication as an Indian Standard without deviations. Certain conventions and terminologies are, however, not identical to those used in Indian Standards. Attention is particularly drawn to the following:
a) Wherever the words 'International Standard' appear referring to this standard, it should be read as 'Indian Standard'; and
b) Comma (,) has been used as a decimal marker while in Indian Standards the current practice is to use a point (.) as the decimal marker.