Numerical analysis of compressed plates with a cut-out operating in the geometrically nonlinear range

Abstract

Article citation info: (*) Tekst artykułu w polskiej wersji językowej dostępny w elektronicznym wydaniu kwartalnika na stronie www.ein.org.pl IntroductionThin-walled load-carrying structures are characterized by high strength and rigidity as well as low weight. Given the above properties, these structures are widely applied not only in the aerospace and automotive sectors, but also in designs where low structure weight is crucial. A disadvantage of thin-walled structures is that they are prone to loss of stability under compressive or shearing loads [2, 3, 9, 13, 21-25, 28, 29]. Nonetheless, thin-walled structural elements can operate even after their stability loss provided that they do it in the elastic range [11,14,21,27]. These structures are particularly sensitive to geometric inaccuracies, which is critical regarding their use. For this reason, they must be precisely manufactured to prevent premature loss of stability. Uniform thin-walled plates are relatively cheap to produce, yet they can carry relatively low loads due to their low flexural rigidity. When subjected to compression, these plates lose stability even under small loads. With common methods for improving load capacity such as the use of stiffeners or ribs, the form of a structure is not only considerably modified, but its weight can increase, too. However, there is a way in which load capacity of thin-walled structures can be greatly improved while the structures themselves can be used as both carrying structures and elastic elements. This can be done by forcing these structures to operate in a higher buckling mode (flexural and torsional). To do so, it is necessary to make a cut-out in the plate and slightly displace the vertical zone in the opposite direction. This displacement will be realized in a special frame -so that the jump on basic mode was impossible. In this way, the plate acquires the desired characteristics, i.e. stable operation in the post-buckling range.Issues of the stability and post-buckling behaviors of plate structure with all sorts of holes was described in [19], where you can find a very comprehensive review of the literature on this issue. At that work as the author of the earliest elaboration, in numerical terms, is given Pennington Vanna [16], who as first considered the problem of the stability of elastic uniaxially compression plate with a cut-out. The article presents the results of FEM calculations and compared to the results of experimental studies. The earliest post-buckling behavior analysis of plate structures with cut-out are reported in [18]. A major contribution brings the works [15,17,20,30], where are considered the postcritical states and limited carrying capacity of this type of structures. Not encountered of research, where was investigated plate structures with cut-out and in which attempted to force of the higher flexural and torsional mode deformation of the structure.In the researched load-carrying structure, one can clearly distinguish a vertical zone where this thin-walled element undergoes com...

Experimental and Numerical Study of the Buckling of Composite Profiles with Open Cross Section under Axial Compression

“…They offer a solution to the problem of non-linear stability of the investigated thin-walled structures using experimental and numerical methods [15][16][17][18][19][20]. The investigations of critical and post-critical states as well as the damage of thin-walled composite columns are reported, for instance, in the works [6,7,14,15,[21][22][23][24][25][26][27][28], where the authors present different methods for describing the problem of nonlinear stability Fig. 1 Post-critical equilibrium paths of a plate without initial deflections and of a real structure and validate the developed numerical models in the experimental tests.…”

“…To this end it is necessary to use approximation methods which -based on the post-critical equilibrium paths of a real structure determined in the experiments -enable determination of the critical load. This problem was examined regarding structures made of isotropic materials, for instance, in the work [10,24], and with respect to composite structures in the works [5,7,27,28]. They do not offer, however, a complex procedure which would enable developing an unequivocal methodology for determining the experimental critical load.…”

Experimental and Numerical Analysis of the Compression of a Thin-Walled Composite Plate

“…In such cases, definition of limit load structure elements requires analysis also able post-critical until the destruction of the structure. In the worldwide literature, studies into nonlinear problems of stability of thin-walled structures can be found easily, for example Koiter [13], Debski [5,7], Kopecki [15,17], Mania [21] and [9].…”

Numerical Analysis of the Behavior of Compressed Thin-Walled Elements With Holes

“…The main problem with steel and composite structures is stability loss, an issue widely described in numerous research publications [1,2,5,6,8,15]. Despite the occurrence of buckling, compressive loads can still be carried by the tested structures, even after exceeding the post-critical condition.…”

“…The problems of stability loss and post-critical behavior of thin-walled elements with holes have been described in the publications [6,19]. Axial compression is a common problem in everyday operation of building structures with vast usable areas.…”