Applied Mechanics and Materials Vols. 170-173

Abstract: In construction of the steel roof a computer-controlled lifting construction technology was adopted. It differed from other similar projects in some points. First, the steel roof had large area, long-span and huge weight; next, the structure form in lifting process differed from the design status; at last, the deformation of steel roof in lifting process could not been ignored. If these characteristics could not been considered in lifting process, it maybe bring large project accident. So in this article the finite element model of the structure in the lifting status had been rebuilt. Considering the displacement difference the lifting process had been analyzed. By the analysis the influence of the displacement difference of the lifting points could be found out. Comparing with the value of the construction measure the finite element model could be validated and corrected. The conclusions of research could be used by the similar construction.

Abstract: In order to treat efficiently with the soft multi-layers in the middle of ground, the improved cement-soil double mixed pile is developed and the pile diameter is enlarged in the soft soil layer depth to form the cement-soil mixed column with bearing load plate. The installation mechanism, deep mixing machine, and pile installation procedure of the soil-cement mixed pile with bearing plate is presented. The field test results show that the cement-soil mixing pile with bearing load plate construction technology can ensure the cement mix content and mixing uniformity. The pile strength is greatly higher than conventional cement-soil pile, so it can be used to improved soft multi-layered ground economically and effectively, and it has a good potential application for practice.

Abstract: In order to provide reliable designing parameters for steel scaffold, anti-slipping tests are carried out on right angle couplers and swivel couplers, including single coupler and parallel-mounted double swivel couplers, with five grades of residual applied torque on belts of couplers. When applied torque is below 50Nm, the anti-slipping load bearing capacity ascends with torque. When the applied torque is greater that 60Nm, some couplers rapture suddenly. The working torque of couplers should be 40-50Nm. At this stage, the load bearing capacity of coupler is at its peak.

Abstract: Based on the original construction experiences and techniques of cable dome, the method of integral assembling on the ground and synchronous hoisting of the structure of cable dome is firstly put forward. With the cable dome built in Ordos, the integral hoisting method and tension-shaping technique are put into effect. The results indicated the integral hoisting method can reduced aerial work and guaranteed constriction security.

Abstract: Henan Art Center has a new curtain wall structure - the structure cable net glass wall. Because of the cable net structure for glass curtain wall construction and design difficulties, the design of curtain wall performance to deepen the main points of cable net structural wall of the working principle, design connections, cable net structural wall of the cable construction steps, cable pre-stressing and tension when the technical parameters and under the glass curtain wall materials and installation was introduced. And the main factors affecting the performance curtain wall and the cable tension when the ambient temperature and the tension stress was studied. The results showed that the construction program was optimize and construction quality and safety was ensure.

Abstract: There were many factors which caused cracks in the concrete beam, but some factors were often not be attention enough. In this paper, Combined with three kinds of crack occurrence in construction of concrete plate, the reasons leading to crack by construction technology were analyzed in detail, which including the construction process, curing conditions and controls of cover thickness, and the solution were given also. The result of analysis had guiding roles of crack controlling in concrete structure construction.

Abstract: Mechanical behaviors of square honeycombs cores (SHCs) are investigated by using the finite element (FE) simulations under the in-plane dynamic crushing loadings. With the increasing impact velocities, different deformation modes are observed. The force-displacement curves include four regimes with distinct characteristics. The plateau stresses are calculated for the SHCs with different configuration parameters. The dynamic plateau stress is the sum of the static plateau stress and the dynamic enhancement due to the inertia effect. The static plateau stress is proportional to the relative density of SHCs. The dynamic enhancement stress is proportional to the square of impact velocity and the relation coefficient depends on the configuration parameters. The empirical formulas of dynamic plateau stress in terms of configuration parameters and impact velocity are given.

Abstract: Underwater blasting as an important part of engineering explosion processes engineering characteristics which contains a wide applied range, high technical requirement and complicated measurement and etc. Based on a project item on underwater explosion conducted by port department in Guangzhou, This paper has studied and simulated underwater explosion on multiple models under different conditions. Further more, the relation among major variables is quantized and the influence caused by certain variables comprehensively is elaborated. The research results may offer the guidance for similar projects.

Abstract: The experiment was carried out and a good quality titanium-steel composite plate was obtained. In the experiment, the base plate made of Q235A and cladding plate made of TA2 titanium plate with thickness 2mm were used and explosive welding parameters were chose reasonably well which are the explosive welding clearance (h) is equal to between 0.4 to 0.6cm and the density of blasting agent in cladding plate (Wc) is equal to 6.2g/cm². The designed titanium-steel composite board with 500×500×14mm can meet the demand in the requiement of ltrasonic inspection stretching inflection anti-shearing property in one type of National Standard of titanium-steel composite board (GB/T8547-2006)

Abstract: The finite element (FE) model designed in Part I is used to obtain the cushioning mechanical parameters of square honeycomb cores (SHCs) under in-plane dynamic loadings. A simplified energy absorption model is proposed to evaluate the energy absorption performance of SHCs, which shows that the optimal energy absorption per unit volume is related to dynamic plateau stress and dynamic densification strain that are affected by configuration parameters and impact velocity. The optimal energy absorption efficiency is the reciprocal of dynamic densification strain. The dynamic plateau stress has been discussed in Part I. For SHCs, the dynamic densification strain is independent of impact velocity and determined by configuration parameters. The empirical formulas of cushioning mechanical parameters are derived from physical analysis of FE results. Based on these empirical formulas, the practical cushioning optimization algorithm is presented.