Applied Mechanics and Materials Vols. 501-504

Abstract: After the Wenchuan Earthquake on May 12 2008, the highways from Dujiangyan to Wenchuan, a crucial passage from Chengdu to Sichuan Western Plateau and Gansu province, are always seriously endangered by landslides, debris flows and their following hazards. Hundreds of debris flows from watersheds, gullies and slopes on July 10 2013 produced fatal hazards and destruction on the Highway G213 and the Express Highway from Yingxiu to Wenchuan. The debris flows are characterized by numerous-occurrence, large flux (645~2238m³/s) and large magnitude (5~126×10⁴m³) as well as the hazard chain process which is composed of debris flow, dammed lake and outburst flood. The highways were seriously destructed and blocked in 16 sites, which were induced by 6 collapsed bridges, 3 submerged bridges, 3 buried tunnel entrances, 1 site collapsed highway base and 7 sites buried highway base or bridges, and the traffic was completely interrupted. Based on analyzing the destruction modes of highways, it was found that the large-scale and potential debris flows and the irrational location of some sections, vulnerable protection measures and low resistant capability of highways against debris flows were responsible for huge highway destructions. Considering the active debris flows in the future at least 5~10 years, it was strongly suggested that potential debris flow identification, integrated management of disastrous watershed, dangerous road line altering, increasing and strengthening protection constructions at dangerous section and improving highway reconstruction standard should be carried out for highway protection and traffic security.

Abstract: A parametric variational principle is deduced according to the equivalent integral form of all the controlling equations and boundary conditions in elasticity, and by adjusting the parameters, all kinds of variational principles put forward past and some new variational principles can be gained, which means that the method above is more clear in concept, and more concise.

Abstract: The flattening behaviour of angle section beams subjected to pure bending is studied in this paper. Analytical solutions for static instabilities of angle section beams subjected to pure bending about its weak axis are derived using energy methods. Nonlinear finite element model using the code ANSYS is developed to simulate nonlinear snap-through instability of angle section beams under pure bending. The optimization assumption about flattening shape of the leg is proposed, through comparison of between the present solutions, experimental results, and the finite element results.

Abstract: The hybrid boundary node method (Hybrid BNM) is a boundary type meshless method which based on the modified variational principle and the Moving Least Squares (MLS) approximation. This paper apply the Hybrid BNM to thin structures. No plate and shell theories are used. Theory analysis of the feasibility of the Hybrid BNM for thin structures is proposed. Numerical result shows that the Hybrid BNM is suitable for thin structures and high accuracy can be observed.

Abstract: In this article, a kind of structural strain controlled reliability method was presented. The interval extension of multi-objective control algorithm was applied to control the structural strain reliability. The method has realized the goal of controlling the multiple static interval reliability indexes by the control of the structural interval parameters. In order to accelerate the speed of the structural reanalysis, the Epsilon algorithm was used in the process of the structural reanalysis when a wide range of modification happened in the interval parameters. This method can both get a satisfactory accuracy, and improve the speed of the reanalysis. Numerical examples show that the method is effective and feasible.

Abstract: A novel approach is suggested for the stress and failure analysis for the pure bending of composite tubes made up of layers of angle 0° or 90° together with other arbitrary angles. The new unified coefficients as well as their nonsingular parameters are introduced to overcome the problem in an earlier approach where some of the parameters are singular for a few layer orientations even though the stresses and displacements are nonsingular. It is pointed out that such singular terms in the earlier approach cannot be simply eliminated as the conventional technique for the singular terms in the stresses in the form of polar coordinates. Otherwise, the continuity conditions at the interface between special and ordinary layers cannot be satisfied. In addition, the Tsai-Hill theory is employed for the failure analysis. Since the stresses are explicit, it is possible to exactly predict the failure positions so the calculations can be dramatically saved. The flexural stiffnesses as well as the maximum moments and their failure positions of the tube [90/±45/0] with different thickness of every layer are derived for the application and design in engineering.

Abstract: In this paper, the neutral surface model of the laminated plate vibration isolation device is constructed based on the APDL parametric design language. While the contact analysis is done, the loading and solution studies are complete. Then the stress and strain graphs which change with different loads such as stress, tension, and turning force are obtained. The result shows that the stress of rubber is close to the steel plate under the turning force, but the former deformation is clear than the latter one.

Abstract: In this paper, nonlinear analysis of arch plate ultimate bearing capacity and the process of nonlinear ultimate failure were conducted by ABAQUS finite element software. The numerical failure simulation of steels, arch plate under different external loads and the separation of concrete as well as the whole slippage of concrete were operated. A reference for the further design calculations of reinforced concrete arch plate structure is provided as well.

Abstract: The mechanical properties of low-yield-point (LYP) steel and its advantages as seismic steel are introduced in this paper. The theoretical equations of inelastic shear buckling stress at the pure shear action for the LYP steel are derived from unified theory of plastic buckling. The relationship curve of inelastic shear buckling strength and width-thickness ratio of LYP steel shear wall at the different height-width ratios of plate is given through iteration calculation process. The effectiveness of theoretical equations used for calculating the buckling stress is verified by experimental results.

Abstract: In this paper, the equivalent inclusion method is used to calculate the elastic fields of a two-dimensional plate containing any number of ellipitical inhomogeneities. Both the interior and the exterior Eshelbys tensors are used in this method. Numerical examples are given to assess the performance of the presented method. The solutions obtained with this method have been checked and confirmed by the finite element analysis results.