Abstract:
An inertial mass amplification type tuned mass damper is disclosed. The inertial mass amplification type tuned mass damper comprises a hollow box, an H-shaped mass block, gears a, gears b, a rectangular frame, a steel ring, viscous dampers, a steel sheet, springs, rotating shafts and balls. In the present invention, an inertial damping force is amplified by adjusting the radius ratio of the gears a and the gears b; and damping parameters can be conveniently changed by adjusting the mass of the mass block, the spring stiffness and the like. The present invention has the advantages that the design mass is small, which can avoid the adverse effects of excessive additional gravity on the structure and improve the performance of the structure. The present invention has reasonable design and small occupied space, can save more use area for buildings and can greatly improve the utilization efficiency of the buildings.
Abstract:
A method for determining a reduction factor of a bearing capacity of an axial load cylindrical shell structure relates to stability checking of main bearing strength thin-walled members of aerospace and architectural structures. Different from experiment experience-based conventional defect sensitivity evaluating method represented by NASA SP-8007, a depression defect is introduced in a manner of applying a radial disturbance load. First, an influence rule of a depression defect amplitude of a single point to an axial load bearing capacity is analyzed by using numerical values, so as to determine a load amplitude range; then, defect sensitivity analysis is performed on depression defects of multiple points; then, experiment design sampling is performed by using load amplitude values and load position distribution as design variables; and finally, based on optimizing technologies such as an enumeration method, a genetic algorithm and a surrogate model, the most disadvantageous disturbance load of the multiple points that limits the defect amplitude is searched for, and a reduction factor of the bearing capacity of the axial load cylindrical shell structure is determined, so as to establish a more physical method for evaluating the defect sensitivity and the bearing performance of the axial load cylindrical shell structure.
Abstract:
A wind field interpolation simulation method based on isogeometric sampling, the main steps of generating a wind speed time series in the present invention are as follows: first, inputting basic parameters of wind field simulation and the number of initial sampling points, and selecting the sampling points by an isogeometric sampling method. Then calculating the maximum relative error of all frequency bands by a relative error defined, and judging a fitting error and an allowable error given. If the fitting error is greater than the allowable error, increasing the number of sampling points and reselecting the sampling points; if the fitting error is less than or equal to the allowable error, finishing point selection, and using an interpolation function to calculate a lower triangular matrix required by the simulation. Thus a fluctuating wind field can be generated by a harmonic superposition method.
Abstract:
A structure multi-dimensional loading test system considering real complex boundary conditions considering real complex boundary conditions comprises a main part of machine, a base part, a hydraulic power supply and a control system. The system can simulate the load borne by a structure in a real working environment better and more accurately, realize multi-dimensional loading of the structure with six degrees of freedom in space and provide more real and valuable experimental data for the research on damage of reinforced concrete materials, components and structures under the action of an earthquake, and the research results will help researchers further reveal the damage mechanism of reinforced concrete structures, put forward the corresponding damage criteria and develop the corresponding seismic design methods.
Abstract:
The present invention provides a multi-phase wavefield inversion method considering both body waves and surface waves in half-space of rock media to address the deficiency in existing methods that neglect surface wavefields. In the present invention, Rayleigh components that strictly satisfy standard elliptic polarization characteristics in a half-space are extracted with Snell's Law of complex angles and the forward modeling and inversion theory of body waves. Then, the phase separation is executed to separate the body and Rayleigh waves. The pre-arrival components of S-waves are truncated to solve optimal incident angles of body waves. Thus, a Rayleigh wavefield inversion is implemented with ground Rayleigh components, and a body wavefield inversion is implemented with ground body components and their incident angles. Finally, based on linear elastic characteristics of the half-space of rock media, single-phase body wavefields and Rayleigh wavefields are superposed to form total multi-phase wavefields with the linear superposition principle.
Abstract:
The present invention belongs to the technical field of structural vibration control, and provides a composite axial energy consumption device based on piezoelectricity and shape memory alloy, comprising a screw, steel pipes, stiffening ribs, steel sheets, bolt-nuts, piezoceramics, screw caps and SMA wire bundles. The mechanical energy of the structure under pressure is converted into the electric energy of the piezoceramics and then the electric energy is converted into heat energy, so that energy consumption efficiency is high and mechanical performance is good. The SMA wire bundles have large tensile bearing capacity, shape memory effect and good corrosion resistance and fatigue resistance. The number of the segments and the specifications of the piezoceramics and the SMA wire bundles can be adjusted according to the actual needs, so that the structure can be adjusted according to the size of an axial force and specific stress conditions.
Abstract:
The present invention discloses a coupling beam eddy current damper with shear displacement amplification. The coupling beam eddy current damper with shear displacement amplification comprises a rigid rod, rotating shafts, a pin column, pins, levers, screws, thread sleeves, copper sheets, permanent magnet components, a steel structural component, balls, ball supports and an outer shell. When vibration occurs, coupling beams on both sides of the damper are relatively vertically displaced; at this moment, two levers move up and down relative to the rigid rod; the movement causes the screws and the copper sheets to rotate; the copper sheets rotate in a magnetic field, then induced electromotive force will generates inside the magnetic field, thereby generating eddy current in the copper sheets. The eddy current effect will produce a damping force that impedes the rotation of the copper sheets.
Abstract:
--The present invention belongs to the technical field of disaster prevention and reduction of transmission lines, and provides a quasi-static calculation method for lateral unbalanced force of transmission lines. The present invention can quantify significant unbalanced force caused by a failed tower to an adjacent tower, thus to quantitatively evaluate cascading failure risk of transmission lines. The present invention does not need a lot of iteration, and can parametrically reveal influence of various factors on unbalanced force. The present invention quantifies influence of large deformation effect of a conducting wire on wind load, and at the same time, wind load of the conducting wire is corrected by the trapezoidal equivalent wind pressure proposed, which avoids wind load calculation error of the conducting wire caused by a relatively large vertical height difference, better reflects actual mechanical state of the lines, and optimizes existing wind load calculation method of transmission lines.--
Abstract:
An intelligent layout design method of curvilinearly stiffened structure based on image feature learning. Firstly, the design variables of the curvilinearly stiffened structure are determined based on the path function. The autoencoder network is built to complete the learning of the structural characteristics of the image, and the transfer learning of the model is further carried out. The convolution neural network is built to complete the learning of the image set with mechanical response labels. Finally, the evolutionary algorithm is used to optimize the layout of the curvilinearly stiffened structure based on the model. The invention solves the problem that the traditional optimization method is difficult to deal with the optimization design with many and variable design variables, and is expected to become one of the most potential technical means involved in the layout design of components in the engineering field.
Abstract:
The present invention belongs to the technical field of energy consumption and vibration reduction of assembled building structures, and provides an energy-consuming connecting device for a prefabricated assembled wall. The present invention provides a normal connection function between walls, and also has the functions of energy consumption and vibration reduction. A used viscoelastic material can provide energy consumption and weaken the cold and hot bridge effect, which is beneficial to building thermal insulation. Meanwhile, the energy-consuming connecting device for the prefabricated assembled wall can be connected with a prefabricated wall in advance, which can be carried out at the same time as the wall is inserted during construction, thereby effectively increasing the construction efficiency. Through the design of clamping groove devices, the wall can be connected firmly and reliably while generating displacement and consuming energy. A multi-segment fixing plate is used to replace full-length arrangement to save the steel.