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In practical applications, asymmetric sandwich panels with tapered and junction regions are frequently used. Under uniaxial compressions, asymmetric sandwich panels are collapsed with complex failure mechanism, and its mechanical behaviour is affected by tapered regions. For structure safety consideration, it is necessary to systematically investigate the stability and damage behavior of full-scaled asymmetric sandwich panels under uniaxial compression experimentally and numerically. For comparison, symmetric sandwich panels were also studied. Quasi-static compression tests and numerical modeling were conducted. Experimental data were sufficiently recorded and carefully analyzed. Meanwhile a nonlinear finite element model was advanced for evaluating stability and predicting failure behaviours and load-bearing capacity of test specimen. Comparisons between numerical predictions and experimental measurements showed that a good agreement was achieved. The tapered region had significant influence on stability behavior and load-bearing capacity. It intensified the asymmetry and introduced additional bending moments into asymmetric sandwich panels and thus caused early local buckling. Thicker core thickness enhanced the structural stiffness and load-bearing capacity. Large amounts of matrix cracking, fibre push-out and core-skin delamination were captured in asymmetric sandwich panels. Overall, buckling occurred in symmetric sandwich panels instead of local buckling in asymmetric sandwich panels, and brittle fibre breakage dominated the failure. [ABSTRACT FROM AUTHOR]

This paper studies the critical issue of thin-walled beams with laterally fixed ends. The method for defining the formulae of twist moment for the beams subjected to combined loads was elucidated. Based on this, the governing differential equations of the beam were developed. The procedure for determining the critical state of the beam by the energy method was presented. With this procedure, the critical state of the beam concerned under three types of loadings such as axial force F , bending moment M and distributed load q (or concentrated load P) was examined deliberately. The outcomes were presented in explicit closed-form, which can be illustrated in 2D and 3D graphs. Also, the analytical solution obtained was in agreement with the numerical one obtained by the commercial software NX Nastran. Furthermore, the analytical solutions were applied straightforwardly to explore the stability and design optimization of the tooth-blade for the new frame-type saw machine under an eccentric load. The result can also be promisingly used to study problems of thin-walled beams with laterally fixed ends subjected to other types of loads. [ABSTRACT FROM AUTHOR]

The non-linear in-plane stability of pin-ended circular shallow arches is analytically investigated. The arches are made of functionally graded material with the material properties varying along the thickness. The external load is a radial concentrated force in the direct vicinity of the crown. The effect of the bending moment on the membrane strain is included in the one-dimensional model. The equations of the pre-buckling and buckled equilibrium are derived using the principle of minimum potential energy. Analytical solutions are found for both bifurcation and limit point buckling. Extensive parametric studies are performed to find and demonstrate the effect of various parameters on the buckling load and in-plane behaviour. It is found that most arches have multiple stable and unstable equilibria and the number of equilibria increases with the modified slenderness. When the load is applied exactly at the crown, the lowest buckling load is related to bifurcation buckling for most geometries and material compositions but when there is a small imperfection in the load position, only limit point buckling is possible. The position of the load can have quite a huge influence on the buckling load, therefore pin-ended functionally graded shallow arches are sensitive to small imperfections in the load position. • The sensitivity of shallow arches to small loading imperfections is studied. • The arches are made of transversely FGM. • The effect of various geometrical-material parameters is investigated analytically. • Results show that the load position has huge influence on the buckling behaviour. [ABSTRACT FROM AUTHOR]

For compression members with primarily axial forces, steel angles with bolted connections are often used. Due to the eccentric connection on only one leg additional bending moments are acting on the member, leading to a complex load carrying behaviour with flexural and/or lateral torsional buckling phenomena. The paper mainly focuses on the presentation of the influence of realistic end support conditions at the gusset plates on the member capacity in compression. In the first part of the paper, about 300 existing test results for steel angles in compression with bolted connections are prepared in such a way that they can be compared with different design rules. This was achieved through the common representation of all test results as a function of the normalized slenderness λ ¯ v about the weak axis. In the second part, systematic numerical calculations are conducted for limit cases of the stiffness of the boundary condition of the load-introducing gusset plates (rigid/hinged). The results are also presented in dependency of the relative slenderness λ ¯ v . The consolidation of all tests and numerical results shows (besides the well-known difference between one-bolt and two-bolt connections) a very high influence of the end support of the gusset plate. [ABSTRACT FROM AUTHOR]

This paper presents a design proposal for the out-of-plane buckling resistance of prismatic beam-columns subject to axial compression and uniaxial major-axis bending that was developed based on the well-known Ayrton-Perry format. Firstly, the relevant theoretical background is summarized, closely following the theoretical derivation performed by Szalai and Papp (2010). Secondly, the required transformations for the engineering application of the design procedure are detailed and extended to arbitrary bending moment distributions. Appropriate generalized initial imperfection factors for the out-of-plane buckling of beam-columns are defined so as to achieving complete consistency across the stability verifications for columns, beams and beam-columns. The proposed procedure is subsequently validated against a large set of advanced numerical simulations. A good agreement was found between the numerical results and the estimates provided by the proposed design procedure, both in terms of the overall trend and the specific quantitative results. Based on a statistical assessment, the comparison with the interaction expression of Eurocode 3 (2005) (method 2) showed that this proposal slightly outperforms the Eurocode procedure, both in terms of average values and dispersion of results. [ABSTRACT FROM AUTHOR]

In the field of structural engineering the design of cost efficient structures is highly important. This led to the development of cold-formed steel structures (CFS). An advanced CFS structure is introduced in this paper, which uses a special type of polystyrene aggregate concrete (PAC) as bracing material. This material has beneficial insulating and fire protection properties, which makes it a reasonable choice for residential buildings. An experimental program was performed, to gain information on the flexural and axial behaviour of PAC-braced CFS elements and panels. Both unbraced and braced members were tested to gain information on increment of load-bearing capacity. Several different element sizes were used to be able to investigate the different stability failure modes (i.e. local, distortional and global). Results showed that PAC was able to restrain the global and distortional buckling modes of steel elements, thus providing “full bracing” in most practical cases. These results are introduced in two papers (Part I and II), detailing the failure modes, load increments and the effect of composite action. In this paper – Part I – the background and the results of bending tests are presented, and the experiments on the compression elements are detailed in Part II [1] . [ABSTRACT FROM AUTHOR]