Applied Mechanics and Materials Vols. 744-746

Abstract: A new method to infill the opening in the precast fabricated concrete shear wall was applied in China. In this paper, three geometrically identical precast fabricated shear wall specimens were constructed and tested under constant axial load and quasi-static cyclic lateral loading. The only difference among three specimens was the methods to infill the opening in the middle, the methods were respectively integration infill, masonry infill and without infill. The hysteretic curves, the skeleton curves, the failure process, the strain variation of reinforcement, the stiffness, the ductility and energy-dissipating capacity were obtained. The results and analysis showed that integration shear wall owns good seismic performance. Its bearing capacity, stiffness, energy-dissipating capacity are excellent while ductility is relatively poor. Masonry infilled wall and wall without infill also own good seismic performance.

Abstract: A contrast investigation of the seismic behavior of unreinforced masonry walls with window openings strengthened with Carbon Fibre Reinforced Polymer (CFRP) sheets and sprayed Glass Fibre Reinforced Polymer (GFRP) is presented. Three wall specimens in the scale of 1/2 were tested by the horizontal cyclic loading combined with constant gravity loads. The seismic strengthening effects by two different FRP retrofitting schemes are compared in aspect of the hysteresis response, deterioration of rigidity and ability of energy dissipation. The experimental results indicate that the increasing degree of the improvement of seismic behavior of the SGFRP-strengthened wall are significantly superior to that of the wall strengthened with epoxy-based CFRP; and the overcoat of sprayed GFRP can bond tightly and work well together with the masonry to play a critical role in earthquake resistance.

Abstract: The destructive effect of salt corrosion on concrete has attracted wide attention of civil engineering scholars nowadays. The west area in Jilin province is not only the typical frost soil region, but also is the most serious area with saline soil. In such environment damage of structural engineering often occurs under the action of freeze-thaw cycles and salt corrosion due to the lack of concrete durability. In this article Da’an city in Jilin is selected to be as the research area, and the physical and chemical properties of soil samples in spring are analyzed, the results indicate that the component of soluble salt in soil mainly includes Na⁺, HCO₃^-, Cl^-, and SO₄², and small amount of Mg²⁺, Ca²⁺, K⁺, and so on. In order to study the influence of different soluble salts on concrete durability under the condition of freeze-thaw cycles, quick freeze-thaw cycling tests on concrete durability are conducted respectively in sulfate, chloride and bicarbonate solution. Then the characteristics and laws of concrete corrosion damage under freeze-thaw cycles and salt corrosion damage are summarized.

Abstract: Experimental study was performed on the hysteretic performance of H-beam to square tubular column connection with diaphragm-through. The main study parameters are the diaphragm thickness and planar dimension. The experiment shows that the bearing capacity and ductility of the connection are sufficient and the strength degradation is stable as well as the stiffness degradation. This kind of connection meets the requirements specified by current seismic design codes.

Abstract: The paper presents the results of studies proposing to use steel hoop and mortise-tendon joint (SHMT), to reinforce beams with defects (biological corrosion, cracks) in order to restore their load-bearing capacity. The proposed solution, consisting in encapsulated or bonding steel tube outside of the damaged part, is suitable for restoration work in historic buildings. Moreover, owing to the fact that the reinforcing steel tubes are situated outside the lap joint , the possibility that the crack of reinforcing joint will reduced and the fire resistance of the element is increased. The displacement loading control method was adopted in bending test. The restoration in the load-bearing capacity of the tested beams amounted from 4.42% to over 44.52%.

Abstract: This paper investigated the failure mechanisms of the stone masonry dome constructed in the heritage site at Jerash. Jerash is the remains of a Roman ancient city and is located 48km north from Amman, Jordan. West Bath in Jerash had one main dome and two small domes. Domes were constructed from stone masonry. The structural characteristics of the remained small dome were investigated numerically by use of the finite element method. The foundation of the West Bath is under the conditions of a land sliding and was cut beside the dome pier. Therefore, assuming the several uneven settlements of the piers, the structural behavior of the dome was assessed. From the distributions of the cracking and the crushing of the stone, the failure mechanisms of the stone masonry were represented.

Abstract: This paper adopts finite element software ABAQUS to simulate the sheet pile wharf with separated relieving platform. Referred to the centrifugal test by Nanjing Hydraulic Research Institute, based on proper simplification and assumption, operating mechanism and characteristics of sheet pile wharf with separated relieving platform are researched from a new angle. Besides, main influence factors are chosen for further analysis, which provides a reference for designing calculation and optimization of sheet pile wharf with separated relieving platform.

Abstract: In order to verify the feasibility of ABAQUS, finite element simulation analysis is used to a castellated steel reinforced high strength concrete beam (CSRHSC beam) firstly. Then we consider the strength of steel, strength grade of concrete and thickness of steel protective layer as parameters to study the mechanical properties of the beam by ABAQUS. The results show that: The bearing capacity of beam increases when the steel strength improves, but the magnitude of increase will gradually reduce with the increase of steel strength. Along with the strength grade of concrete increase, the yield strength and ultimate strength basically tend to linear increasing, the ductility tend to decreasing. With the increase of thickness of concrete cover, the ductility of the beam improves but the ultimate strength decreases.

Abstract: This paper describes the results of a fire test conducted on two-way slab with two edges clamped and two edges simply supported. The details of support condition, arrangement of reinforcement, position of displacement transducers and thermocouple trees are described. The experimental results such as the temperature distributions within the slab, vertical deflections and horizontal displacements are presented. The experimental results show that the temperature distribution along the slab depth was nonlinear and the temperature gradients in the slab were large. Main cracks near the clamped edges occurred on the top surface of the slab. It is shown that two-way slab with two edges clamped and two edges simply supported has good fire resistance.

Abstract: Extended finite element method (XFEM) can effectively describe the phenomenon of steel node cracks growth and extension. In this paper, extended finite element method is used for the beam weld node end under the concentrated load to analyze node fracture under no initial crack and pre-crack condition. The result shows that: under the no initial crack condition, crack appears near the weld root, where the bottom and upper of the weld is easy to crack than the middle,because of the necking phenomenon,which means that both end stress is higher than the middle. Crack firstly appears in the weld bottom, extending from the bottom to up. The crack tip makes stress concentration, which accelerates the crack extension. The location of the pre-crack has the influence on the node fracture, which means that the farther the position from the weld root is, the harder it is to crack and grow. Pre-crack position coincides with no initial crack extension path, promoting crack growth and extension.