Seismic Analysis of 3D Framed Building

Generally RC framed structures are designed without regards to structural action of masonry infill walls present. Masonry infill walls are widely used as partitions. These buildings are generally designed as framed structures without regard to structural action of masonry infill walls. They are considered as non- structural elements. RC frame building with open first storey is known as soft storey, which performs poorly during strong earthquake shaking. Past earthquakes are evident that collapses due to soft storeys are most often in RC buildings. In the soft storey, columns are severely stressed and unable to provide adequate shear resistance during the earthquake. Hence a combination of two structural system components i.e. Rigid frames and RC shear walls or Rigid frames and Bracings leads to a highly efficient system in which shear wall and bracings resist the majority of the lateral loads and the frame supports majority of the gravity loads.

Stability Characteristics of a Vibrating System with Double Rigid Frames Driven by Four Co-Rotating Coupling Vibrators

In this paper, a dynamic model is adopted to investigate the stability and response characteristics of a vibrating system driven by four vibrators placed on two different rigid frames (RFs). Using the equations of motion of the system derived, the conditions for synchronization and stable operation of the system are studied by the average method and Hamilton’s rules, respectively. Based on the theoretical results obtained, some factors are further studied concerning the stable phase differences (SPDs), the coefficients for ensuring stability, and the vibration amplitudes of the two RFs in different resonant regions. These serve to reveal the stability and response characteristics of the system that determine the ultimate function of the vibrating machine. Finally, numerical simulations are carried out to examine the validity of the theoretical methods and numerical qualitative results. Based on the results from the theory and simulation analyses, it is suggested that the working region of the system should be selected in the sub-resonant region corresponding to the natural frequency (NF) of the main vibrating system in the [Formula: see text]- and [Formula: see text]-directions. In this case, the ideal relative circular motion for two RFs with a well isolation effect can be achieved, and the energy is saved.

Stability and motion characteristics in a vibrating system with five rigid frames driven by two counter-rotating exciters

A new dynamical model with five rigid frames (RFs), driven by two counter-rotating exciters, is proposed to explore the synchronization, stability, and motion characteristics of the system in this paper. The motion differential equations and the corresponding responses of the system are given firstly. Using the average method, the average torque balance equations for the two exciters are deduced. According to the relationship between the difference of the dimensionless effective output electromagnetic torques for the two motors and the coupling torques of the system, the theory condition of realizing synchronization is obtained. Based on the Hamilton’s theory, the theory condition of stability of the system is deduced. The stability and motion characteristics of the system for different resonant regions are qualitatively discussed in numeric, including the stable phase difference of the two exciters, relative phase relationships among the five rigid frames, amplitude-frequency characteristics, stability coefficients, and the effective load torque between the two exciters. Simulations are carried out to further quantitatively validate the feasibility of the above theoretical and numerical qualitative results. It is shown that in engineering the reasonable working points of the system should be selected in Region II, only in this way, can the synchronous and stable relative linear motion of the system with the zero stable phase difference in vertical direction be realized, and in this case, the vibrations of the four inner rigid frames (IRFs) in the horizontal direction are compensated with each other, and the energy is also saved due to utilizing the resonant effect. Based on the present work, some new types of vibrating coolers/dryers or vibrating screening machines can be designed.

Theory, numeric, and experiment studies on stability of two homodromy vibrators in a vibrating system with double rigid frames

The synchronization and stability of two or more vibrators in vibrating systems with double rigid frames are rarely investigated in previous studies. To make up this drawback, we take a dynamical model with double rigid frames driven by two homodromy vibrators, for example the synchronous and stable states of the corresponding system, as well as the relative motion characteristics between the two rigid frames, are analyzed in detail. First, the mathematical modeling of the system is given; the absolute motion and relative motion differential equations of the system are deduced. After that, the theory conditions of implementing synchronization and those of stability are obtained, by using the average method and Hamilton’s principle, respectively. Based on the theoretical results, some numerical qualitative analyses are provided to reveal the coupling dynamical characteristics of the system, and the corresponding ideal working regions are suggested. Finally, experiments are carried out to further examine the validity of the theoretical and numerical results. The present work can offer a reference to design some new vibrating machines such as the considered model.

Numerical Analysis of Rigid Frame Joint with Textile Carbon Reinforcement

Benefit of textile reinforced concrete (TRC) is absent of necessary concrete cover because of the durabulity. It allows creating concrete slabs only about 10 mm thick. Therefore, TRC going to be very popular, and more often used in design and load-bearing structures. Big problem in designing of load-bearing structures are rigid frames. The aim of this paper is clarify behavior of thin concrete rigid frames with carbon textile reinforcement by numerical analysis and influences of carbon reinforcement anchoring to the crack opening. Model was created in Atena Science as 2D model and necessary parameters were determined by experimental tests.