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Determining the boundary conditions of the structure is a very important aspect in the failure
analysis. In experimental tests, the method of compressed composite samples significantly influences the
obtained results. In numerical studies, there is a problem of correctly defining the boundary conditions
applied in real object. The present paper includes study to determine the influence of the elastic
pads on the thin-walled laminated angle column under shortening. Analyzed samples are made with
carbon-epoxy laminate using the autoclave method. The configurations of laminate layers are: [60,02,-
602,603,-602,03,-602,0,602]T, where direction 0 is along the length of the profile. The buckling and
the post-buckling states of the columns were investigated experimentally and numerically. Firstly, a
simply supported angle columns subjected to uniform shortening are tested experimentally. Due to the
stress concentration between the real sample and the grips, flexible pads were used. Experimental tests
are carried out on the universal testing machine. The deformations of columns were measured by using
the non-contact Aramis System. The composite material condition was monitored by AE (acoustic
emission) using the Vallen Systeme with piezoelectric sensors. Next, the numerical calculations in
Abaqus software based on the FEM (finite element method) are performed. To determine the influence
of an elastic pads, two numerical models of the system with and without flexible pads are developed.
In order to estimate damage initiation load in numerical models, a different damage criteria ( Tsai-Hill, Tsai-Wu, Azzi-Tsai-Hill, Hashin) are used. Based on the results specified that the model with elastic
pads more accurately reflects the actual behaviour of the L-profile element under shortening. It was
supported, i.a. by good agreement of flanges deflection (the equilibrium paths) with experimental
results. A qualitative and quantitative agreement of damage initiation load was obtained using Hashin
criteria. The present study was supported by statutory resources allowed to the Department of Applied
Mechanics, the Lublin University of Technology under “The Grant for Young Researchers“ no. FNM
30/IM/2020.
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