PSI - Issue 71

M. Mohan Kumar et al. / Procedia Structural Integrity 71 (2025) 333–339

334

compared to a conventional wing under similar operating conditions. In the current study, the Just-in-time Prepreg (JIPREG) fabrication process was used to design and produce the composite wing of a two-seater trainer aircraft. As part of a weight optimization initiative, the thicknesses of the wing components were optimized based on stiffness and strength criteria. The optimized design was then subjected to finite element analysis for various critical flight and landing load scenarios. To comply with JAR VLA standards, the design was further validated through a full-scale static strength test of the wing. 2. Structural design of composite wing The composite wing is composed of a top skin, bottom skin, and nine ribs each on the left-hand (LH) and right-hand (RH) sides, two shear attachment spars, a main load-bearing spar, two Main Landing Gear (MLG) attachment spars and skins. The skins, spar webs, and ribs are constructed using a sandwich design, with glass bi-directional fiber composite as the face sheet material and foam as the core. At attachment points, the foam core is substituted with a plywood core and aluminum reinforcement for added strength and stiffness. The main spar flange is made from monolithic carbon composite. Fig. 1 illustrates the geometric details of the composite wing.

Figure 1. Outline dimension diagram of composite trainer aircraft wing (mm).

3. Finite element analysis of Composite wing 3.1 Finite element analysis model

In the finite element analysis, HyperMesh software was employed for mesh generation, boundary condition setup, and other pre-processing and post-processing tasks. MSC Nastran was utilized as the solver. The finite element model consisted of triangular and quadrilateral shell elements. The wing components, including the skin, spar, ribs, flanges, and control surfaces (ailerons and flaps), were meshed using 2D elements such as QUAD4 and TRIA3, with the PCOMP card applied in the NASTRAN solver. The wing's finite element model included a total of 55,319 elements, comprising 54,827 CQUAD elements and 1,302 CTRIA3 elements. The complete finite element model is illustrated in Fig. 2.

Fig. 2. FE model of composite aircraft wing with control surfaces.