Load-capacity prediction for the carbon-or glass-fibre-reinforced plastic part of a wrapped pin joint

Abstract

A joint using a metal pin is one possibility of how to achieve a removable joint of composites. The load capacity of a wrapped pin joint depends on many parameters, especially on the types of fibres and resin, and geometric properties of the joint. The composite part of a wrapped pin joint is exposed to a combination of the tension in the longitudinal direction and local compression in the transverse direction. The values of the compressive stress in the transverse direction can exceed several times the uniaxial compressive strength. In this work, CFRP (carbon-fibre-reinforced plastic) and GFRP (glass-fibre-reinforced plastic) parts of wrapped pin joints were tested. Experimental specimens with different geometries were exposed to a quasi-static loading. A Zwick/Roell Z050 testing machine was used for the tensile tests. Moreover, the load capacities of the carbon or glass composite parts were determined using a finite-element analysis. A new measure based on the LaRC04 criterion was proposed for the prediction of the load capacity. The numerical and experimental results were compared. Keywords: composite, finite-element method, load capacity, loop criterion, wrapped pin joint Spoji z uporabo kovinskega zati~a so ena od mo`nosti, kako dose~i odstranljivo kompozitno povezavo. Nosilnost zavite sti~ne povezave je odvisna od mnogih parametrov, posebno od vrste vlaken in smole ter geometrijskih lastnosti povezave. Kompozitni del zavite zati~ne povezave je izpostavljen kombinaciji napetosti v vzdol`ni smeri in lokalnim tlakom v pre~ni smeri. Vrednosti tla~nih napetosti v pre~ni smeri lahko ve~krat prese`ejo enoosno tla~no trdnost. V tem delu so bili preizku{eni zaviti zati~ni spoji z deli iz CFRP (plastika, oja~ana z ogljikovimi vlakni) in GFRP (plastika, oja~ana s steklenimi vlakni). Preizkusni vzorci z razli~no geometrijo so bili izpostavljeni kvazistati~ni obremenitvi. Za natezne preizkuse je bila uporabljena naprava Zwick/Roell Z050. Poleg tega je bila nosilnost kompozitnih delov z ogljikovimi ali steklastimi vlakni dolo~ena z uporabo analize kon~nih elementov. Novo merilo, ki temelji na merilu LaRC04, je bilo predlagano za napovedovanje nosilnosti. Primerjani so numeri~ni in eksperimentalni rezultati. Klju~ne besede: kompozit, metoda kon~nih elementov, nosilnost, merilo zanke, zavit spoj s kovinskim zati~em

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