Numerical strength analysis of a wooden and a composite wing structure

Cilj ovog diplomskog rada je usporedba svojstava drvene i kompozitne konstrukcije krila malog aviona najveće poletne mase do 450 kg. Konstrukcija krila je preuzeta iz besplatnih nacrta za ultralaki avion drvene konstrukcije Chilton DW-1, namijenjen za samogradnju. Prema tehničkoj dokumentaciji izrađen je CAD model krila u programu Solidworks, pri čemu su uvedena pojednostavnjenja i prilagodbe na geometriji u cilju bolje diskretizacije numeričkog modela. Potom je na temelju prvotnog modela izrađen izmijenjeni model krila kojem je dio drvenih komponenata zamijenjen kompozitima. U programu Abaqus/Standard provedena je statička numerička analiza obiju konstrukcija. Iznosi faktora normalnog opterećenja preuzeti su iz karakterističnih točaka V-n dijagrama prema EASA-inim normama. Raspodjela aerodinamičkog opterećenja modelirana je prema podacima dobivenim analizom u programu XFLR5. Na modelu kompozitne konstrukcije krila je zatim provedeno dimenzioniranje komponenata prema Hashinovom kriteriju popuštanja do postizanja željene čvrstoće, nakon čega je uspoređena ukupna masa drvene i kompozitne konstrukcije krila.The aim of this thesis is to make an FEM model of an existing wooden wing design for an aircraft with a MTOW of less than 450kg, and to compare its mechanical properties to those of an equivalent composite wing design. The wooden wing of a Chilton DW.1, a light racing aircraft designed for homebuilding, has been used as a basis for the CAD wing model. The model was designed using Solidworks, with many details simplified to facilitate mesh discretization with a minimum of distorted elements. A second wing model was then designed by replacing the main load-bearing members of the first model with equivalent members made of carbon fibre-epoxy composites. Both models were imported into Abaqus/Standard to perform static FEM analyses. The load factors used in the analysis were obtained from EASA regulations. The wing lift distribution was modeled according to results obtained by a flow analysis performed using XFLR5. The composite components were then sized according to Hashin failure criteria, with the aim to withstand the assigned loads with no damage initiation occurring