Papers by Keyword: Experiment

Abstract: The experiment and finite element analysis were made to determine the pin-load distribution of multiple countersunk bolted single-lap joints. In the experiment, the pin-load fractions were evaluated indirectly by the lap-sheet surface strains collected from a few rows of strain gages. The joint strains and pin-load distribution were also obtained directly in the finite element analysis. The calculated strains correlated well with the experiment. Nevertheless, the pin-load fraction results of the both techniques are quite different. The further analysis revealed that the procedure of transforming the measured strains into pin loads is not reliable, since the intrinsic additional bending had not been taken into account. Therefore the appropriate way to determine the pin-load distribution should be the numerical analysis validated by the strain measurement. The another attempt showed that the pin-load distribution can be evaluated by the finite element modeling of two-dimensional shells and beams as well with satisfied accuracy.

Abstract: The 2D laboratory experiments were performed to investigate tsunami wave runup on the combined sand beach. The N-wave was generated in three different water depths. The water surface elevations, maximum elevation of runup and snapshots of wave uprush and back wash were measured. The theoretical analysis of runup was presented. The results showed that uprush water wave had a decelerate process. The maximum elevation of runup R depends on incident wave height H and R is linear relationship with H plus water depth h.

Abstract: The shape memory alloys (SMAs) have received increasing interest attributed to their unique superelastic effect and the shape memory effect. The existing models of superelastic SMAs are generally complex for practical use. In this paper, cyclic loading tests of superelastic SMA wires are first performed. Based on the experiments, a simple constitutive model is set up. Simulations testify that the model can approximately describe the hysteretic characteristics of the superelastic SMA and the simulated mechanical parameters agree well with the experimental values.

Abstract: Seven concrete beams were constructed with normal reinforcement bars. Grooves were opened on the concrete cover of the tensile region in the concrete beams using different combinations of carbon fiber reinforced plastic (CFRP) and pre-stressed helical rib bar (HRB), CFRP and HRB pre-stressed at different levels were inserted into the grooves and filled with resin. Flexural experimental results indicated that the limit bearing capacity, rigidity, and crack resistance of the beams were strengthened significantly with near-surface mounted two pre-stressed HRB and one CFRP (BF1P2) bar, or near-surface mounted one pre-stressed HRB and two CFRP (BF2P1) bars, in which HRB was pre-stressed at 30%, 45%, and 60% of its limit strength, respectively. Compared with an un-strengthened beam, the crack loads of the BF1P2 beams increased by 86.70% and 133.33%, the yield loads by 32.25% and 72.04%, and the limit bearing capacities by 72.73% and 90%. The crack loads of the BF2P1 beams increased by 50% and 133.33%, the yield loads by 50.54% and 136.56%, and the limit bearing capacities by 72.20% and 173.60%. The BF1P2 beams had better reinforcing results compared to those of the BF2P1 beams. The beam strengthened with HRB pre-stressed at 45% of its limit strength was the best concrete beam.

Abstract: Taking vibration test on 7 shale ceramsite concrete beams and a reinforced concrete beam, collecting the dynamic signals, and modal analyzing it, this paper studies the ceramsite diameter /strength and the injury at all stages impact on the frequency so as to guide the design and construction of shale ceramsite reinforced concrete structures and components.

Abstract: To analyze the influence of aggregate on shale ceramsite concrete cracks and to compare the crack resistance between shale ceramsite reinforced concrete and ordinary reinforced concrete under the static load, one normal reinforcement beam and seven reinforced ceramsite concrete beams were used to take static experiment by way of two symmetric loading method to get different damages and characteristics of crack beams under load at all levels of distribution.

Abstract: In the interest of an understanding to the imperfection stability behavior, a model of single layer spherical lattice shell was designed. The size and the pattern of initial imperfections were entirely measured. Automatic harmony loading control system and data acquisition system was used. The experiment plan, method and results have provided reference significance for the study on the stability of spatial lattice shell. The experimental results and the results of measured imperfections method were compared and analysed in detail. It is verified that measured imperfections method can accurately take into account of the effect of initial imperfections and it can be used for the supplementary checking computations of some important finished structures.

Abstract: A new reinforcement technique with prestressed helical rib steel wires is presented, and one control beam, three strengthened beams under monotonous loads are tested. The flexural capacity, load-deflection relation, cracks and deformation of reinforced concrete beams are systematically studied under the same initial prestress level and amount of reinforcement, different groove size. The test results indicate that the strengthening technique could significantly improve the first-crack load, steel-yielding load, ultimate load of the beams, and improves the service performance of the strengthened beams. The high performance of the helical rib steel wires is allowed for a better utilization. The results provide a reference for engineering applications.

Abstract: A way of using flexible spiral blade as the executive part for spiral transportion was proposed, the mathematical model of its transportation resistance torque was set up, and the impact of structure parameter of flexible spiral blades on transportation power was analyzed. A experiment set-up was rigged, and tests were made to verify the theoretical model. The results of the experiment are in good agreement with the theoretical analysis. The research has enlightened the the parameter design of flexible spiral blades

Abstract: Researched on the refractory material corrosion by experiments. Each refractory was measured to take four different parts, and the average corrosion thicknesses of silicon carbide, quartz and corundum were 0.52mm, 1.03mm and 1.40mm. The corrosion of corundum refractory was most serious, and quartz refractory had a certain degree of corrosion, but it was not very serious. The corrosion of silicon carbide refractory was the least. In the experiment in intermediate frequency furnace, only upper and lower parts of slag line were connected to the refractory and the degree of corrosion was little for silicon carbide crucible. Slag part of the wall thickness was about 16.6mm after the reaction. Amorphous master alloy parts of the wall thicknessis about 16.9mm. For quartz crucible, refractory corrosion was much bigger, which was 10 mm thick before reaction. The erosion thick was about 2~3mm. It was a little thicker than corrosion experiment in static crucible.