The paper proposes a kinematic scheme of loading the thick-walled composite three-span stringer panel of the wing torsion box making it possible to implement the required compression and shear combination. It provides a description of irregularity zones; their study becomes possible using the proposed bench. The problems that could arise when loading a structurally similar sample of such dimensions are considered; they include large values of the acting loads, implementation of the loading type, complexity in creating the correct boundary conditions, and the resulting edge effects. Special attention is paid to these problems. Computation is performed applying the numerical method in the Abaqus CAE software, its result shows that the specified deformations are achieved. The initial data in computation include geometric model of the wing torsion box three-stringer panel, and the composite material mechanical properties. Computation result shows that the required combination of the compression deformations with shear is achieved. Besides, special attention is paid to narrowing the scoring zone caused by the edge effects. The considered panel loading by combined action of the compression and shear loads represents a scientific novelty; analysis of the loading sources of similar panels shows the absence of a shear component during loading, thereby overestimating the bearing capacity of a test object. Taking into account the shear would allow achieving loading closer to the real one; the results of such testing obtained on the bench would be useful at the earlier stages of design and development of the unit structure. The proposed kinematic scheme makes it possible to repeatedly load a sample to collect and systematize experimental data in studying the irregularity zone and/or defect.

EDN  QAGWQP