Papers by Keyword: Eccentric Load

Abstract: Steel bolt groups are often used for joining steel structures. The design strength of the steel bolt group is related to the geometric distribution, the eccentric load distance, the material strength and the load angle, thus making the analysis complicated and not easy for the user. The existing analysis methods are two kinds of elasticity and ultimate analysis. Both methods consider the stress distribution of each steel bolt and find the steel bolt at the critical position is obtained, the design load analysis is deduced. This study will consider the geometric distribution of steel bolting group affected, for a row, two rows, three rows and four rows of bolt group, considering different eccentric distance and angle of influence. Using a simple elastic analysis method to Studied the strength analysis results produced when a corner bolt is damaged due to a defect. The results show that the greater the eccentric load distance, the lower the design strength, and the load change on the vertical is more obvious than the horizontal. When the corner of the steel bolt group is removed, its design strength is likely to decrease, but at low eccentricity distance and large angles, the strength of the complete bolt is higher. This study organizes the design method of steel bolts and reviews the geometric rules of the bolt group analysis. It founded that the regular geometry needs to be reviewed in the case of large eccentric loads with small eccentricities. This study for the bolt connections strength of a certain understanding and awareness, expect the future for the safety of steel structure contribute.

Abstract: The software ANSYS was used to perform the calculation of combined simulation for the track beams under eccentric load in the third wharf in a shipping company and to check whether the beams meet the requirements of safe use. In order to take into account the horizontal constraints of concrete surface slabs of high-piled wharf on track beams, a finite element model of the structure consisted of a crossbeam and piles was first established to calculate the equivalent spring restraint stiffness. Then the nonlinear finite element analysis of track beams under eccentric load was performed. The results show that the cracking of concrete cover at the tension side and the bottom of track beams under eccentric load may occur, but the tensile steel bars at the bottom of beam do not yield. It is suggested that the track beams under eccentric load must be reinforced to use them.

Abstract: Recent years in Malaysia, precast concrete sandwich panel gained its popularity in building industries due to its economic advantages, superior thermal and structural efficiency. This paper studied the structural behaviour of precast lightweight foamed concrete sandwich panel (PLFP) with double shear truss connectors under eccentric load. Preliminary results were analysed and studied to obtain the ultimate load carrying capacity, load-deflection profiles and strain distribution across the panel thickness at mid depth. The achieved ultimate load carrying capacity of PLFP due to eccentric load from the experimental work was compared with values calculated from classical formulas (if it is more than 1 comparison) developed by previous researchers. Preliminary results showed that, the use of double shear truss connectors in PLFP was able to improve its ultimate load carrying capacity to sustain eccentric load and achieve certain compositeness reaction in between the wythes.

Abstract: 5 masonry columns were strengthened by Sprayed Glass Fiber Reinforced Polymer (SGFRP) in this paper, and a research of the seismic behavior of them tested by eccentric loading experiment was presented. The failure modes of the strengthened masonry columns were illustrated and strengthening effects of them were discussed. The results showed that the bearing capacity of the reinforced columns increased greatly, and the ductility of them also improved significantly. Comparing the strengthening effects of the columns when the thickness of SGFRP and the number of glass fiber are different, some reasonable reinforce suggestions are proposed.

Abstract: Direct calculating method was deduced from the requirements of pressure on foundation bottom surface to avoid loop computing and verified by an example. Worksheet of Excel was created and calculating via Goal Seek of Excel was presented, the initial width value of foundation should not less than 0.12m. The direct calculating method is very simple, convenient and rapidly. Calculating via Goal Seek of Excel is intuitive but you need to know how to use Excel. It is more simple if create another worksheet of Excel via the direct calculating method.

Abstract: In recent years the research on Surface-initiated longitudinal cracking along wheelpath (or Top-Down cracking) is become a fresh hotspot in the field of pavement damage focused by international asphalt pavement engineering.Because the traditional load is the vertical surface load with uniform tire pressure, this loading is applied at only one position and no effort is made to distinguish between tire pattern.The traditional method can’t explain the mechanism of the top-down cracking. In order to discuss the mechanism of TDC, this paper establish a 3D finite element model of semi-rigid pavement structure and use the large finite element software Abaqus. The analysis shows that, in the crack beginning stage, the main tensile stress appears under the center of the load on the sub-base of the pavement,and its value increases with the time. When cracks appear in the base, the position of the main tensile stress appears at the bottom of the surface layer, under the outside edge of wheel path. The value of the main shear stress increases at the stage of the cracks beginning, but the increase is small. The value of the main shear stress decreases when the cracks appear in the middle of the surface layer, and the position of the main shear stress changes with the depth of the cracks. With the increase of the cracks’ depth, the adverse influence of the shear stress becomes weaker and weaker.So the key of controlling the cracks in the surface layer is prevention. To prevent the development of the cracks, the tensile strength of the layer’s material should be enhanced in any way. The stress and its value resulted from the vehicle loaded on the structure layer is bigger than the other cases when the position of the cracks is at the edge of wheel path, and the stress is much bigger than the shear strength and the fracture toughness of the material of the layer. As the shear strength of the material is not enough, the vertical cracks are easier to appear at the edge of wheel path under the load of the vertical. Once it appearing, the cracks will extended into the layer because of the load of vertical. Eccentric load generates greater stress in the structure than the load loaded upright. In fact, though, non-channeling can reduce the appearance of the tracks, eccentric load enhance the development of the cracks in the surface because of the existence of the cracks in the surface layer.

Abstract: This paper compares three standards of FRP strengthened concrete columns published by ACI committee, Concrete Society and China respectively. A test is designed according to the comparison. A total of five columns were cast and tested. The analysis of the load bearing capacity and ductility of the test result indicates that wrapping hoop GFRP can enhance load bearing capacity slightly and the ductility greatly, wrapping axial GFRP can enhance load bearing capacity greatly but the failure of column is brittle, wrapping axial GFRP over-wrapped with hoop GFRP can both enhance load bearing capacity and the ductility.

Abstract: The FE model of the pretightening assembly moving beam of open-die forging hydraulic press is built with FE simulation software ABAQUS in the study. With the FE model, the force status of pretightening assembly moving beam is studied. Then the pretightening force of assembly moving beam is further studied and the computing method of pretightening force is given. The main achievements of the study include: Under pretightening, the stress of main moving beam is very low and that of guild sleeves is also lower than the allowable stress. Under center loading, the stress of the center field of main moving beam is higher and that of guild sleeves is almost same to that of pretightening. Under eccentric loading, the stress of same deviation field of main moving beam is higher and the effect of pretightening force on the stress of main moving beam is very small. The stress distribution of guild sleeves with different pretightening force is same and the effect of pretightening force on its strength is very low. The pretightening force of tension rod can be computed with the force of press, the allowable eccentric value of the workpiece, the distance between up guild section and down guild section of guild sleeve and the quantity of tension rods. The results of the study are very useful to design and install the pretightening assembly moving beam of open-die forging hydraulic press.