Experimental Study on the Shear Capacity of Rabbet Cast-in-Place Prefabricated Beam

In order to investigate the shear capacity of prefabricated beam, experiments about shear bearing were performed on one integral pouring contrast beam and two prefabrication and assembly beams. Inspecting the relationship between load and deflection under the load, the development regularity of strain between longitude reinforced and stirrup, the shear capacity of cracking load and ultimate bearing capacity, analyzing failure mode of oblique section and connection performance of old and new concrete in the groove, and compared with the mechanical properties of cast-in-place concrete beam. The experimental results indicate that: prefabrication and assembly beam and cast-in-place beams have similar shear bearing capacity and failure mode of oblique section, along with the load level continues to increase, the groove joint stiffness weakened, but has little effect on the overall deformation.

Four self-made free surface electrospinning devices for high-throughput preparation of high-quality nanofibers

Four different self-made free surface electrospinning (FSE) techniques, namely, modified bubble-electrospinning (MBE), modified free surface electrospinning (MFSE), oblique section free surface electrospinning (OSFSE) and spherical section free surface electrospinning (SSFSE), designed for high-throughput preparation of high-quality nanofibers, are presented in this paper. The mechanisms of fiber preparation of the corresponding four FSE devices were studied by simulating the electric field distribution using the Maxwell 3D software. The properties of the electric field in the device are very important for the FSE process. The effects of the particular technique on the morphology and the yield of nanofibers were experimentally investigated. The experimental data agree well with the results of the simulations and show that all four FSE devices can be used to prepare large quantities of high-quality nanofibers. A comparison of the spinning mechanisms of these four FSE devices illustrates that the SSFSE device performs best, providing the highest quality and yield of nanofibers. The SSFE device could yield 20.03 g/h of nanofibers at an applied voltage of 40 kV.

Four self-made free surface electrospinning devices for high-throughput preparation of quality nanofibers

Four different self-made free surface electrospinning (FSE) devices, namely, modified bubble-electorspinning (MBE) device, modified free surface electorspinning (MFSE) device, oblique section free surface electorspinning (OSFSE) device and spherical section free surface electrospinning (SSFSE) device, were presented to obtain high-throughput preparation of high quality nanofibers in this paper. The preparation mechanisms of these four FSE device were studied by simulating the electric field distribution using Maxwell 3D, due to the importance of electric field in the FSE process. And the effects of them on the morphology and yield of nanofibers were investigated by experiments. The experimental data agreed with the simulation results of electric field, and showed these four FSE device all could be used to prepare high quality nanofibers in large quantities. Meanwhile, comparing the spinning effects of these four FSE device, the results illustrated the SSFSE device was the optimal FSE device because of the highest quality and yield of nanofibers, and its yield could reach 20.03 g/h at the applied voltage of 40 kV.

Sound absorption of a new oblique-section acoustic metamaterial with nested resonator

This study designs and investigates high-efficiency sound absorption of new oblique-section nested resonators. Impedance tube experiment results show that different combinations of oblique-section nest resonators have tunable low-frequency bandwidth characteristics. The sound absorption mechanism is due to air friction losses in the slotted region and the sample structure resonance. The acousto-electric analogy model demonstrates that the sound absorption peak and bandwidth can be modulated over an even wider frequency range by changing the geometric size and combinations of structures. The proposed structure can be easily fabricated and used in low-frequency sound absorption applications.

Research on the Finite Element Method of Reinforced Concrete Member in Bending Oblique Section Bearing Capacity

With the development of computer science and technology, computer hardware and software conditions have been improved greatly, which can make the finite element analysis of complex structure possible. Reinforced concrete is one of the most commonly used components in building structure, the study of reinforced concrete mechanics is mainly compared through the experiment, however finite element analysis of oblique section stress is not much, based on the theory of combining elastic-plastic mechanics, using ANSYS structure analysis software carries out the analysis of numerical simulation for the oblique section stress of reinforced concrete. Through the stress-strain numerical simulation curve, this paper can get the maximum load of oblique section without corrosion reinforced concrete frame that is0.03N/mm2, finally this paper will choose three different corrosion degree of the reinforced concrete members are to carry on the analysis of numerical simulation, and compared with experimental results, the results prove the reliability of numerical simulation, to provide a reliable basis for the mechanical study of reinforced concrete inclined section.

Numerical Analysis Programming on the Concrete Elastic-Plastic Behavior

Using arc-length method, the progress of solving nonlinear function is discussed for designing new numerical analyzing tool, and the frame of programming based on nonlinear method is compiled. The results from completely restricted modeling show convex deformation and the damage on oblique section. And with the concrete elastic-plastic constitutive used in numerical simulation including add uninstall, typical engineering examples inspect reliability of the elastic-plastic numerical analysis program. This provides the basis and guidance for the future of the specific program design.

Numerical Analysis on Concrete Elastic-Plastic Constitutive under Different Restraints

The fitting curve given by least square method is applied in numerical analyzing. The results from semi-unrestrained and completely restricted modeling show convex deformation and damage on oblique section clearly. Advanced virtual experiment illustrates the differences between loading with displacement and pressure, due to the phenomenon that pressing by force will cause deformation on top surface but displacing load wouldn’t. The fitting idea by orthogonal base function will provide a widely road for studying the constitute law of concrete material. Otherwise, the progress of solving nonlinear function is discussed for designing new numerical analyzing tool, and the frame of programming based on nonlinear method is obtained