ESDU 04017:2010

PREFACE TO FATIGUE – ENDURANCE DATA SERIES

The design engineer concerned with aircraft and their equipment
faces an ever-increasing demand for products with a performance
that must be substantiated under stringent conditions of cost and
environment. Assuming the basic skill of the designer, no other
single factor can contribute more to the economic preparation of a
satisfactory, competitive engineering design than having to hand
good reliable design data.

Data concerning fatigue of aerospace structures are widely
scattered and, when located, are of variable quality and relevance
to industrial applications. The task of collecting and evaluating
all the relevant data available on a particular aspect of aircraft
structures is time-consuming and therefore expensive. Even if such
a task is performed it is often found that the customer will wish
to view the design, not against some locally-derived data, but
against what can be demonstrated to be the best data that can be
ascertained and that are vouched for by a significant cross-section
of the engineering and scientific community concerned with both the
derivation and application of data on fatigue. Accordingly, the
Fatigue Series has been prepared to meet design requirements with
regard to fatigue of aircraft structures for both the designer and
his customer and, by serving the needs of many, accomplishes the
task at much lower cost and with higher reliability than could the
individual.

A qualified staff, with the assistance of many establishments
throughout the world in research, industry and academia, collects
and evaluates the existing data. The staff discards that which is
irrelevant or unreliable, correlating and distilling what remains
into an authoritative working tool for engineering application.
Throughout, the work of the staff is guided and monitored by an
expert group and ad hoc working parties.

The rate of growth of knowledge of fatigue is rapid. It follows
that while the most recent information on a given aspect of fatigue
may have considerable value and usefulness it may be subject to
some modification in the light of further experience. The Committee
has decided that, rather than hold back information of this type,
it should be included in the Series in the form of Tentative Items.
Such Data Items are distinguished by the inclusion of the word
'Tentative' in the title. Such distinction is not meant to imply
that there is doubt as to the reliability of the basic data but
that some qualification of the inferences that may be drawn from
the results of applying the Item may be advisable. The nature of
these qualifications is noted in the text. All Items in the Series
are subject to frequent review and revision is made where
necessary; Items that carry the designation of Tentative will be
revised and the designation removed as soon as further knowledge
that justifies such a course becomes available.

Unlike many other forms of information, design data are
constantly being generated and tested in practice. Therefore, ESDU
draws its strength not only from the sources of new data but also
from those who apply the evaluated data that it provides.
Accordingly, users of the service are encouraged to regard ESDU as
a widely-based group of people available to answer questions and
discuss the application of data in engineering.