Applied Mechanics and Materials Vols. 166-169

Abstract: This paper first adopts variational inequation—the method of linear complementary equation. We use this method to analyses the elastoplastic limit load of space grid structure. This is a way to resolve the nonlinear question. Adopting this method to resolve the limit load of space grid structure avoid some drawback caused by adopting iteration method. We only need do some limited compute to a load-increment then we can obtain consequence, which fit in with all condition. Particularly, though adopting the method of linear complementary equation, we can control the value of limit load, make the calculated load can not exceed the limit load. Once exceeding, computer can decrease load- increment automatically and load again till getting the limit load of structure. Based on elastoplastic limit load analysis, this paper has considered big deformation impact on the limit load of bspace grid structure. We have made analysis of doubly nonlinear limit loads under the condition of coupling out of elastoplastic big deformation. The method and theory of this paper can combine with all kinds of single rod mechanics model.

Abstract: Gravity platform was widely used in marginal oilfield, so the strength and the stability of its marine riser under wave load became very important. By simplifying the Morison equation, the paper made the dynamic analysis of the riser come down to solving the fourth order non-homogeneous linear differential equation, thus got the analytical solution of its deflection, shear force and bending moment. And the comparison with Ansys simulation showed that this simplified method was feasible.

Abstract: Based on the experiment of 8 steel reinforced concrete T-shaped columns specimens under monotonic static shear load, test value of shear crack load were obtained. Influence on shear crack load because of the shear span ratio, axial compression ratio and stirrup ratio was analyzed, the added coefficient θ of flange and α of steel were introduced. The calculation formula for shear cracking load was given. It is shown that shear cracking load reduces as the shear span ratio and increases with the axial compression ratio increases within a certain range, shear cracking load increases with stirrup ratio increasing, the calculated value of shear cracking load is in good agreement with the experimental data.

Abstract: Textbooks of plasticity mechanics have given example for elastoplastic analysis of structure composed of columns, but the given example is solved with the method of material mechanics. There is actually some difficulty to solve the structure composed of columns with the basic equation system of the classical plasticity mechanics. The new equation system of plasticity mechanics based on e-p curve has advantage over the classical one. In this paper, the solution will be really obtained with the basic equation system of plasticity mechanics based on e-p curve, which is not only a job to solve a simple problem with the basic equation system, but also a demonstration to show that the new equation system of plasticity mechanic based on e-p curve is correct and practicable.

Abstract: This paper presented a progressive collapse analysis of spatial composite frame with concrete-filled steel tubular (CFST) columns. A typical finite element analysis (FEA) model of a 12-story building was established by using ABAQUS. The shell elements were used to simulate the slab, and all of the steel beams and CFST columns were simulated by the beam elements incorporating nonlinear material and geometric, respectively. Nonlinear dynamic analysis was carried out for the sudden loss of columns for different scenarios of column removal, and the capacity of progressive collapse resistance of the 3-D composite frame and other components internal force around the removed column were investigated.

Abstract: Flange connection has been applied widely, and many researches have been done on flange connection both at home and abroad. But the existing research on flange focused on bearing capacity, and there were few reports on the rigidity of flange. In this paper, rigidity test was carried on for the connection of rigid flange and flexible flange in substation frameworks. According to the test results, the tensile rigidity, shear rigidity and flexural rigidity was compared. The results indicated that the tensile rigidity, shear rigidity and flexural rigidity of flexible flange connection was lower than those of rigid flange connection with high strength bolts.

Abstract: To investigate the effect of the horizontal construction joint on seismic behavior of the exterior joint of the reinforced concrete frame structure, the numerical simulation of the exterior joint with the construction joint under the low cyclic loading was done. The experimental results and the numerical simulation values were compared. Seen from the ultimate load, the experiment value is 158.7kN, the simulation value is 170kN, the relative error is about 11%.Further analysis of the exterior joint of reinforced concrete frame skeleton properties, the feasibility of applying unit construction joints is verified.

Abstract: Bamboo-steel composite structure is a new structure type, which has outstanding advantages of light weight, high strength, energy-saving and environmental protection. Components of this structure use bamboo plywood and cold-formed thin-walled steel as main materials, which are combined by structural adhesives. This paper presents an analysis approach of the bonding properties of bamboo-steel interface under static load.

Abstract: The fatigue of grid structures with welded hollow spherical joint under suspending cranes is an issue in both academic and engineering fields at home and abroad. The structural fatigue is mainly caused by the fatigue failure of welded hollow spherical joint with cross-board. In this paper, 16 specimens categorized in KQ-4、KQ-5 and KQ-7were tested stably and efficiently under constant amplitude stress by use of self-designed loading equipment. The testing results show that the form and mechanism of fatigue failure were clarified elementarily. A fatigue curve of welded hollow spherical joint with cross-board, S-N curve, was suggested in this paper based on the statistic regression analysis of the 16 testing results. The constant amplitude fatigue calculation method was established for welded hollow spherical joint with cross-board in grid structure with welded hollow spherical joint by use of allowable stress amplitude method.

Abstract: Recently, self-drilling screw connection is the most primary connection way in the cold-formed thin-wall steel structure, many scholars have studied its stress mechanism and shear capacity. This paper begins with several self-drilling screw stress mechanism and shear failure mode, introduces the domestic and international calculation, then summarize and analyze the research progress on the self-drilling screw. At last, prospect on the self-drilling screw shear capacity and application.