Mechanical joints in composite laminates- a complex stress function based pin loaded hole approximation
Date
2015-01-09
Authors
Bidgood, Peter Mark
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Abstract
Classical laminate theory is a well known theory for obtaining the properties and
stress distribution in a layered orthotropic laminate. This theory, however, only
applies to laminates o f in finite size, where disturbances in the stress field as m ay be
caused by free edges, holes or cu t-outs are not present.
Methods o f calculating the stress distributions and behaviour o f holes and pin-loaded
holes in a composite laminate have been investigated.
This dissertation presents a computer program written in the "C" programming
language as implemented on a personal computer. T h e theory is based upon the
original work o f Lekhnitski (1947) [Ref], as further developed and presented b y De
Jong. T he theory is briefly presented. The method is an "alternative to the more
expensive method of finite element modelling and is derived from the solution o f the
governing differential equation by means cd complex stress functions.
T he program, (BHOLES), is a data generating module which generates the stress
field in the vicinity of a hole or pin-loaded hole in a laminate specimen of arbitrary
width to hole diameter ratio.
Alternative methods o f presenting and analysing the generated data have been
investigated but no direct comparison is made with experimental results.
T h e accuracy of the generated data is verified b y several methods including
correlation with data generated by an independently developed program. Indirect
reference to test results obtained by D e Jong [2] is used to indicate the effectiveness
o f the model.