Advanced Materials Research Vol. 684

Abstract: Internal erosion is one of the main causes of instabilities within hydraulic earth structures. The occurrence of breach in new structures underlines the emergency to quantify phenomena induced. Over the years, several methods have been developed to characterize and model internal erosion. The intention of this paper is to present a new experimental device named Cross Erosion Test (CET) and devoted to the characterisation of internal erosion. This test consists of the injection, in a first drilling, of clear water and the recovery, in another drilling, of water charged with particles. With this technique, main processes occurred can be identified. Moreover, preliminary experimental results show the possibility to characterize suffusion into a specific soil.

Abstract: The random character of mechanical properties of building materials reveals itself when construction structures are tested even though all prescribed technological standards and requirements are met. The paper presents software implementation of the algorithm the statistical straggling of the mechanical properties of materials in the design of structures. This algorithm is built into the software AnSysBuildingBlock (ASBB), developed by us, whose interface is presented here, and which can automatically generate the code for the settlement complex ANSYS. Consider an example in which the impact of scattering mortar mechanical properties on the stress-strained state of brick masonry and its structural destruction was investigated.

Abstract: In this paper, a new disaster relief housing unit is proposed, and its structural performance under cyclic loading conditions is investigated. This housing unit is composed of a series of identical unit wall panels, which are made up of steel angle frames, steel rods for diagonal bracing and sheeting elements. The lateral load resisting capacity of only a single wall panel is examined by performing a test on three specimens. The theoretical lateral strength of the wall panel is estimated and compared with the test results. The contribution of sheeting elements, generally treated as nonstructural components, is considered, and the energy dissipation capacity of the proposed unit is also evaluated. The results of the test show that the addition of sheeting elements is helpful to enhance the peak lateral strength of the panel frame and the steel diagonal bracing is very effective in enhancing the peak strength of the unit wall panel at initial stages, but not the overall ductility of the structure.

Abstract: Various maintenance problem has been reported according to the increase in service period of steel structures. It is difficult to examine and evaluate the corrosion problem and phenomena because of its uncertainty based on the environmental condition. Thus, the corrosion characteristics of the carbon steel were investigated to analyze the corrosion effect of carbon steel on the different atmospheric environments. The atmospheric exposure tests on uncoated carbon steel plates were conducted, to examine the corrosion phenomena and to obtain a fundamental corroded surface under different corrosion atmospheric environments. The corrosion characteristics of the carbon steel were compared depending on their different atmospheric environment and their exposure periods.

Abstract: Shear behaviors of a web panel are changed by web boundary conditions and web panel with free web boundary has been reported by severe corrosion damage. In this study, post shear buckling behaviors of web panel with free-lower web boundary was examined to evaluate its shear failures and strengths depending on its web boundary changed by corrosion. Thus, nonlinear finite element analyses were carried out to identify their post buckling behaviors. Their shear behaviors and shear failure mode were compared as well as comparisons of their behaviors depending on aspect ratio and boundary conditions.

Abstract: In the past few decades most of the efforts were made to achieve minimum weight of the steel structures by satisfying all the design requirements imposed by various latest building codes and this idea lead towards the concept of pre-engineered steel buildings (PEB). In current research work, minimum weight buildings are targeted with simple fabrication process and easy erection to have maximum structural efficiency. Minimum weight of structure is proportional to the minimum cost and hence lowers seismic and gravitational forces. To achieve above mentioned objectives and to verify the suitability and applicability of concept of PEB, a sample steel industrial building is first analyzed and designed by using conventional steel hot rolled sections and then by using pre-engineered tapered and cold formed sections. Results of analysis were compared in terms of weight and response of structures which clearly indicated that PEB structures are of less weight and structurally more efficient than conventional steel structures.

Abstract: Using the recently proposed Finite Particle Method (FPM), this paper presents the rigid-body contact simulation of 3D structures. The FPM models the space truss with finite particles. Following Newton's second law, every particle is in a permanent dynamic equilibrium. Fictitious motion procedures are developed in the particle internal force calculation to handle the geometric nonlinearity without iterative correction. Contact model and corresponding algorithm are developed based on the FPM. A numerical example is presented to demonstrate the capability of the FPM for analyzing rigid-body contact problems.

Abstract: To multi-tower suspension bridge, reasonable design of middle tower is very important. In this paper, a three-tower self-anchored suspension bridge (TSSB) was taken as research background. The effect of middle tower stiffness and mass on static and dynamic performance of TSSB was discussed. Through dynamic characteristic analysis, we got the modes whose nature frequencies were affected obviously by middle tower stiffness. The seismic parameter analysis showed that rigid and light weight middle tower was benefit to seismic performance of TSSB. At last, this paper concludes that designer should consider static and dynamic performance of TSSB comprehensively in the design of middle tower.

Abstract: The effects of applied stress and test temperature on the environment-induced cracking (EIC) behavior of carbon steel in 5 kmol/m3 NH4NO3 solution were investigated by using constant load method. The three parameters (time to failure (tf), steady state elongation rate (lss) and transition time to time to failure ratio (tss/tf)) were obtained from a corrosion elongation curve. The relationships between applied stress and the three parameters were divided into three regions; the stress-dominated, the EIC-dominated and the corrosion-dominated regions. Under an applied stress of 225 MPa (in the EIC-dominated region), the test temperature dependences of the three parameters were investigated. Although tf decreased with increasing test temperature above 323 K, it became constant independent of test temperature under 323 K. Whenever the EIC takes place, the relationship between log tf and log lss become a good straight line with a slope of -1.1 irrespective applied stress and test temperature, which means that lss becomes a parameter for predicting tf. In addition, the fracture appearance in the EIC-dominated region was intergranular. From the results obtained, the intergranular cracking of carbon steel was discussed in terms of film formation, dissolution and hydrogen permeation.

Abstract: Due to the use course limitation of asphalt pavement at home and abroad, research on road asphalt recycling is laid particular stress on an aging regeneration properties both in China and abroad at present, and research on multiple aging and regeneration is much less. In this paper, five heating tests of 40 min, 85 min, 180 min, 240 min, 300 min were carried on to simulate asphalt aging , and reentry another same time aging after regeneration for each aging asphalt, so reciprocating cycle five times, each group of sample use the same reclaiming agent to regenerate NO.70# road asphalt after every aging test. The experimental results show that: after aging regeneration many times, performance index of NO.70 road asphalt can return to no age level, namely the asphalt multiple recycling is completely feasible.