Papers by Keyword: Bolt

Abstract: An experimental study of tensile failure behaviors of L-shaped adhesive-bonded and bolted hybrid composite joints, which are designed to connect composite cabins, is performed. A set of rigid jigs was designed to fix the specimens and ensure to apply an axial tensile load. The damage processes, failure loads and ultimate failure patterns of the joints are obtained from the tests. Some indentation around the fastener hole and remarkable discontinuity departure between the top and bottom L-shaped laminates which leads to the catastrophic failure can be observed on the specimens. It follows that the discontinuity is the weak spot and required to be strengthened.

Abstract: In the case of the column materials to determined, the lower natural frequency of column is determined by the number of coupling bolts and bolt arrangement. In this paper, by three-dimensional modeling software of Solidwork column model of hobbing is set up, then by using ANSYS finite element analysis software. The initial four order natural frequency to the different number of connection bolts and the different arrangement of bolt are respectively calculated. After the initial four order natural frequency are contrasted, we conclude that in the case of merely considering dynamic stiffness this study reach it is the most reasonable to select 8-12 bolts in the hobbing of YKQ31300, and different bolt arrangement of effects on the dynamic stiffness of the column is very small and can be ignored.

Abstract: This Traditional joints used for the restoration of historical timber structures are not designed according to standards. A very common joint is a vertical splice skew with a key. Unfortunately, the forces mutually acting in its separated parts are not known. It is only their limits that may be derived with some accuracy, but even this is very valuable for practice. The accurate values may be obtained from measurements or experiments.

Abstract: The three-dimensional solid models of five different length and shaft diameter anchor of bolt were constructed based on ANSYS software, and making static analysis and modal analysis on it to obtain the stress nephogram and natural frequency of bolt. Research on the stress condition of bolt in static analysis. In modal analysis, researching on the effect regular of the change of length and shaft diameter size on the bolt transverse vibration, the longitudinal and torsional vibration of three natural modes of different frequency, providing a reference for the structure design and reasonable choice of bolt type for corresponding condition.

Abstract: People remained optimistic about the safety of the space grid structures, because the seismic damages of space grid structures were quite rare and rather light. However, two space grid structures got damaged in 2013 Lushan Ms 7.0 earthquake. The two structures are the double-layer reticulated shell structure and flatbed grid structure, namely Lushan Gymnasium and Lushan Middle School Gymnasium respectively. This paper briefly reviews the seismic damage phenomena of grid structures in historical earthquakes, and then focuses on the two damaged space grid structures in Lushan earthquake. The reason why the two space grid structures got damaged are derived from the force state analysis of the rods, ball joints and bearings. Finally, we come up with the effective advice for the seismic design and construction of the space grid structure.

Abstract: Five groups of vibration experiments were carried out on the 6.8 grades and M20 bolts and nuts that used on transmission tower. The test result shows that the basic way to improve the anti-loosening property was increasing the initial preload. Both increasing initial torque and appending lubrication can obviously increase the initial preload, however appending lubrication may reduce it's anti-loosening property under the situation of same preload. In the vibrating process the second stage plays a decisive role for anti-loosening property, it can be expressed as reduced rate “K” of the preload.

Abstract: Aim of this article is in presentation of results of dynamic tests of round timber bolted connections with slotted in steel plates. Multicyclic dynamic (fatigue) tests in tension were made with round timber joints on pulsator INSTRON in laboratory of ITAM CAS Prague. Results of laboratory tests have been statistically evaluated and completed with graphical records of deformation response to loading.

Abstract: This paper presents the results of static tests of round timber bolted joints with inserted steel plates. All round timber joints static tests in tension were carried out on pressure machine EU 100 in laboratory of the Faculty of Civil Engineering VŠB-TU Ostrava. At first, timber specimens were tested without reinforcement. Based on these results, mechanical reinforcement methods were proposed: using modified washers and boost with screws. These samples were also tested. Rate of improvement in tensile strength was established for used reinforcement method.

Abstract: Based on tension tests for tower bolt, it was found that the pretension increased with the extension of torque retention time, and manifested characteristics of decreasing at early stage then increasing at later stage during the tension process, that provided guidance for bolt fastening.

Abstract: We obtain response regularity of stress wave in bolt, which regularity can be applied in nondestructive testing of anchoring quality, with establishing longitudinal one-dimensional bolt wave equation, studying longitudinal vibration responses under several boundary conditions by the principle theory of elastokinetics. And it is the principal theory that anchoring quality is deduced by bolt vibration response which is caused by dynamic transient vibration.