Advanced Materials Research Vols. 163-167

Abstract: Corrosion of ocean engineering steel structures leads huge economic loses each year. To decrease corrosive loses and guarantee the safety of ocean steel structures, on the basis of Database on Corrosion of Ocean Engineering Materials and Structures (DCOEMS), the overall architecture of a digital simulation system is proposed based on the collection of existing models of corrosion damage on marine steel structures. Typical models involving uniform corrosion, pitting corrosion, stress corrosion and corrosion fatigue are sorted out and integrated in the simulation system which makes a thorough analysis for calculation and principle of professional module. The effective integration of corrosion damage, structural simulation and visualization is implemented successfully. It achieves the applications of the digital simulation. In the case of prediction and evaluation, it lays a good foundation for the development of the simulation system with independent intellectual property rights.

Abstract: The static stability capacity is the main index to measure the whole mechanical performance of single-layer latticed shells. Three single-layer cylindrical latticed shells with different height to span ratio were modeled, and their seismic damage were assessed by the degradation of static stability capacity incurred by earthquakes. Two different static load patterns were considered: dead load and the combination of dead load and half span live load. The results show that the damage assessment method is applicable to single-layer cylindrical latticed shells, and the static load patterns have no big influence on the damage assessment of the single-layer cylindrical latticed shells.

Abstract: The modal analysis and the calculation of dynamic response of the Fenghua Bridge, a new type of long-span steel arch bridge, are carried out using the finite element software ANSYS. Through the on-site testing, the vibration frequency and the change of dynamic displacement response with different weight and speeds are obtained by the DASP data processing software. It is found that the field test results are in consistent with the theoretical results. Firstly, the natural vibration period is 2 ~ 3 times longer than the other ordinary arch bridges, which indicate the bridge structure is stable; Secondly, the dynamic displacement of bridge deck changes in the same direction with weight, while in the opposite direction with speed, and the maximum appears on the midpoint of the middle span; Finally, the maximum dynamic displacement is 11.41mm, which doesn’t exceed the allowable value. So it can be concluded that the bridge is safe under the vehicle-bridge coupling vibration.

Abstract: An experimental study was performed to investigate the structural capacity of composite steel plate walls with trilateral constrained. Six one-third-scale models of one-story prototype walls with composite steel plate shear walls were tested. The parameters for this test were the width-thickness ratio of infill steel plates and the strength of compound precast plate. Regardless of the infill plate design, the steel plate wall specimens exhibited excellent strength, deformation capacity. The design of boundary connection method is important to small width-thickness ratio of infill plates. Bolt sliding between the infill steel plates and boundary frame would decrease initial stiffness and shear strength of the steel plate shear walls. And more, this result indicates that the initial stiffness and shear strength would be improved highly with compound precast plate as resistant-lateral of infill steel plate. But the precast plate must be have sufficient strengh in design.

Abstract: A simplified seismic design model on steel truss coupling beam is suggested based on compatible distortion and balance conditions, considering second order effect and perfect plasticity. This model regards web members of the coupling beam as constraints, thus just the chord need be studied instead of the whole truss. End moments and end shears of chords and relations between distortions of components of the truss and displacement of the coupling beam are established. So curve of load-displacement, plasticity formation and development and influences of area of web members on ductility are convenient to obtain. Results show that this model is more convenient and accuracy than finite element method. Finally some valuable conclusions about influences of span-to-depth ratio and area of web member on ductility of the coupling beam are acquired to contribute to design.

Abstract: Unloading is a complicated process that the load-carrying condition of main structure is gradually transferred and the internal force is redistributed, and so the exact numerical simulation applied on the unloading process is crucially important. The steel roof composed of the space tubular truss with the long-span and cantilevered structure for the Helan Shan stadium at Yinchuan city in Ningxia Hui autonomous region is taken as an analytical example and the finite element analysis software SAP2000 is used to simulate the unloading process during the steel construction. The computational model is established and the simulation method is provided for investigating the detailed unloading process of steel roof. The load-carrying characteristic of every bracing point acquired by the numerical simulation analysis is applied to analyze and evaluate the structural performance under two different comparable unloading cases and then an optimized unloading scheme is achieved from these two cases. The deformation of steel roof and stress ratio of steel member at each different unloading step during the whole unloading process are presented. Ultimately, based on the preferable unloading scheme, the temporary bracing structure is designed by using the maximum reaction of bracing points when unloading.

Abstract: Based on the real construction process and field environment of large sluice pier for Caojie Project, considering the factors of surface insulation, internal cooling, the strength of the foundation and environmental climate, the basic theories of temperature field and stress field of concrete and 3D FEM combining with cooling pipe discrete model and iteration method are used to carry out the study of cracking mechanism. According to the 3D dynamic simulation of the temperature filed and stress field for the pier, reasonable temperature control measures are put forward for reference during construction period. The result of the simulation shows that the concept of the exterior thermal insulation and interior pipe cooling measures are of great useful in practice, and the methods should have great reference signification in future.

Abstract: This paper deals with probabilistic sensitivity analysis for a semi-rigid joint of continuous web plate based on correlations analysis. Firstly, a numerical study was carried out by the software package ANSYS, the finite element analysis was validated compared with experimental results. Secondly, parameters sensitivity analysis was carried on by applying ANSYS Probabilistic Design Analysis. Considering the correlations in primary parameters, all random parameters are varied at the same time based on Monte Carlo simulation. An especial expression between geometric parameters and moment-rotation was discussed. Thirdly, the moment-rotation model of the joint was attained. The composite constant of the moment-rotation model is determined by partial derivative of any parameter from the model. It is concluded that the parameters of the model have notable physical meaning and the proposed model should be accurate and acceptable.

Abstract: A steel footbridge with a 27m net span, a worm-shaped curve and a vine bridge style was proposed to be constructed in Diexi city of Sichuan, China. Considering the appearance and the functional requirement, the bridge is designed as follows: the section outline is composed of 21 different ellipse-shaped transverse ribs with 1.5m spacing, and the transverse ribs are connected by 12 longitudinal ribs. Comparison between two optional structure schemes is carried out. Considering the mechanical performance and economy, the structure scheme, a truss structured system at lower part of the bridge, is adopted. Internal force analysis, member design and deformation calculation of the structure are accomplished. Finite elements analysis with ANSYS shows that the welded joints can meet the bearing capacity requirement. Connection between the bridge and the foundation platform is also presented in this paper.

Abstract: A numerical investigation on the block shear failure behavior of coped beams with double welded clip angle connection was conducted. Parametric study was conducted based on the validated finite element model. The parameters included the web block aspect ratio and the connection rotational stiffness. Based on the mechanical model of double angle connection, the pitch and the beam element length-to-angle thickness (L/t) ratio of the outstanding leg were selected as two importance parameters to consider the effect of the connection rotational stiffness. The results of parametric study show that the connection rotational stiffness has a great influence on the block shear capacity of coped beams with double welded clip angle connection. This is contributed to the fact that for the connections with a smaller connection rotational stiffness, the shear stresses of the shear area were much less than those of the connections with a larger connection rotational stiffness.