Mechanical joints in composite laminates- a complex stress function based pin loaded hole approximation

摘要

Classical laminate theory is a well known theory for obtaining the properties andudstress distribution in a layered orthotropic laminate. This theory, however, onlyudapplies to laminates o f in finite size, where disturbances in the stress field as m ay beudcaused by free edges, holes or cu t-outs are not present.udMethods o f calculating the stress distributions and behaviour o f holes and pin-loadedudholes in a composite laminate have been investigated.udThis dissertation presents a computer program written in the "C" programmingudlanguage as implemented on a personal computer. T h e theory is based upon theudoriginal work o f Lekhnitski (1947) [Ref], as further developed and presented b y DeudJong. T he theory is briefly presented. The method is an "alternative to the moreudexpensive method of finite element modelling and is derived from the solution o f theudgoverning differential equation by means cd complex stress functions.udT he program, (BHOLES), is a data generating module which generates the stressudfield in the vicinity of a hole or pin-loaded hole in a laminate specimen of arbitraryudwidth to hole diameter ratio.udAlternative methods o f presenting and analysing the generated data have beenudinvestigated but no direct comparison is made with experimental results.udT h e accuracy of the generated data is verified b y several methods includingudcorrelation with data generated by an independently developed program. Indirectudreference to test results obtained by D e Jong [2] is used to indicate the effectivenessudo f the model.