The invention relates to a large-thrust rocket engine lateral force test pre-estimating method. The problems that the lateral force of an existing large-thrust liquid rocket engine is unknown, and theapproximate range of the lateral force cannot be determined by means of theoretical analysis and the like are solved. The method comprises the following steps that 1) finite element simulation calculation is carried out on mountain-shaped spring plates; 2) the result of finite element simulation calculation of the mountain spring plate structure is utilized, so that the linear relation between the pulling-pressing force F of the single mountain-shaped spring plate and the strain epsilon is obtained, the linear relation between the bending moment M of the mountain-shaped spring plates and thestrain epsilon is obtained, and k1 and k2 are obtained; 3) the pasting positions of strain gauges on the mountain-shaped spring plates are selected; 4) strain values of the eight strain gauges on thefour sets of mountain-shaped spring plates are measured, and the pulling-pressing force applied to the mountain-shaped spring plates in the X direction and the Y direction as well as the bending moment values are obtained by utilizing the obtained corresponding linear relations between the pulling-pressing force and the strain values as well as between the bending moments and the strain values; and 5) the size and the direction of the lateral force are determined by means of vector summation.

Large-thrust rocket engine lateral force test pre-estimating method

The invention aims to provide a ship acoustic feature intelligent active control method. According to the control method, a perception sensor is used for detecting acoustic and environmental information such as noise signals, pressure and temperature nearby a ship body under the water surface; an acoustic analysis and feature extraction module is used for extracting required radiation noise signals and acoustic situation information nearby the ship body; a control module generates signals at specific frequency and amplitude through an adaptive control algorithm according to the acoustic features and the acoustic situation information and finally realizes control over the acoustic features through a driving module and a transducer. Through the ship acoustic feature intelligent active control method, the voice print features of a ship can be changed to realize acoustic false camouflage for cheating and confusing the opposite side; moreover, noise nearby the ship body under the water surface can be actively offset when necessary to cut down acoustic feature signals of the ship body and conceal itself to achieve intelligent acoustic stealth. Thus, the intelligent active control and acoustic stealth performance of the ship can be improved.

Ship acoustic feature intelligent active control method

The invention aims to provide a ship structure acoustic radiation characteristic intelligent active control method which is used for detecting ship vibration noise, pressure, temperature, and the likeacoustic and environmental information using perception sensors, extracting required ship radiation noise signals and acoustic situation information through an acoustic analysis and feature extraction module, generating signals with specific frequency and amplitude by using a self-adaptive control algorithm according to the ship radiation noise signals and the acoustic situation information usinga controller, and finally controlling the acoustic radiation characteristics of the ship structure through a driving module and an active actuator. According to the method, ship voiceprint characteristics can be changed, acoustic false indication camouflage for spoofing and puzzling the opposite side can be realized, and ship radiation noise reduction, acoustic characteristic signal reduction, hiding and intelligent sound stealth can be realized when necessary, so that the ship intelligent active control and sound stealth performance can be effectively improved.

Ship structure acoustic radiation characteristic intelligent active control method

The invention provides a three-dimensional laminated structure dynamics analysis method, belonging to the technical field of structure dynamics. The core of the analysis method of the invention is that on the basis of the three-dimensional elastic theory, the series of the mixed orthogonal polynomial is introduced into the state space method, and because of the existence of the boundary characteristic function, the limitation of the boundary condition can be effectively overcome, and the multi-boundary condition can be effectively and flexibly processed. Based on the three-dimensional elastictheory and fully considering the lateral deformation and the interlayer continuous condition, the invention establishes a high-precision mathematical model suitable for multi-boundary conditions; In the process of boundary treatment, only adjusting the parameters of boundary characteristic function can realize the effective treatment of different boundaries, without re-modeling or re-programming,to achieve unified treatment, greatly reduce the computational cost and improve the computational efficiency.

A method for dynamic analysis of three-dimensional laminate structure

The invention discloses a high-frequency local response calculation method for a plate structure in a thermal environment, and the method comprises the steps: (1) deducing a general solution and a special solution of a control equation of the plate structure according to the bending vibration control equation of the plate structure in the thermal environment, determining a wave function adopted inthe calculation according to the general solution, and further setting an expression of the response of the plate structure in the thermal environment; and (2) setting a plate structure boundary condition, introducing the boundary condition to obtain each parameter in the expression of the plate structure response in the thermal environment, and calculating the high-frequency response of the plate structure in the thermal environment. Aiming at the problem of high-frequency response calculation of the plate structure in the thermal environment, the method solves the problem that a traditionalstructure high-frequency response analysis method cannot calculate the local response of the plate structure in the thermal environment, and provides an efficient and accurate method for high-frequency response analysis of the plate structure in the thermal environment.

plate structure high-frequency local response calculation method in a thermal environment

The invention discloses a vibration analysis method of an elastic plate structure. The method includes the steps that the Carrera high-order interception technology is utilized for conducting fittingon the thickness-direction displacement of the elastic plate structure; the two-dimensional improved Fourier series is adopted for conducting full-solution-domain expansion on the plane displacement of the elastic plate structure; the overall displacement of the elastic plate structure is obtained through calculation based on the cross-section plane displacement and axial displacement of the elastic plate structure; the strain vector and stress vector of the elastic plate structure are calculated; a strain energy and kinetic energy equation of the elastic plate structure is calculated, and a virtual spring boundary is set to obtain boundary energy; a structural Lagrangian energy functional is established, and a kernel mass matrix and a stiffness matrix of the elastic plate structure are obtained through calculation; the overall mass matrix and stiffness matrix and the characteristic equation of the structure are obtained through an iterative loop kernel matrix; the inherent frequency of the elastic plate structure is calculated, and the vibration mode of the structure is output according to the feature vector. The method is suitable for elastic plate structures with multiple shapesand multiple boundary conditions, high in precision, fast in convergence and low in calculation cost.

Vibration analysis method of elastic plate structure

The invention provides a vibration analysis method for a uniform section beam structure. The method comprises the steps that geometric size characteristics of the beam structure are extracted, a displacement field of the beam structure is separated to be in-section displacement and axial displacement; fitting is performed on the in-section displacement of the beam structure; extension is performedon the axial displacement of the beam structure; the in-section displacement and the axial displacement of the beam structure are combined to calculate integral displacement of the beam structure; strain vectors and stress vectors of an elastic plate structure are calculated; strain energy, a kinetic energy equation and boundary energy of the beam structure are calculated; a structural Lagrange energy function is established to obtain a core mass matrix and a stiffness matrix of the beam structure; an integral mass matrix, an integral stiffness matrix and an overall mass matrix are solved through iterative looping of the core matrix, and then a characteristic equation of the structure is obtained; and a characteristic equation matrix of the beam structure is solved, and inherent frequencyand a vibration mode are obtained through calculation. The method is suitable for the beam structure with multiple boundary conditions and multiple section shapes and is high in precision, fast in convergence, low in calculation cost and simple in calculation method.

Vibration analysis method for uniform section beam structure

The invention provides a laminated shell dynamics analyzing method. The method comprises the steps of 1, extracting coordinates, material and boundary parameters of laminated shell sublayers; 2, usingimproved Fourier series to expand a solution domain of sublayer bottom face and top face displacement; 3, on the basis of the sublayer bottom face and top face displacement, establishing a sublayer dynamics displacement field; 4, on the basis of the three-dimensional elastic theory and a penalty function, setting a sublayer energy fonctionelle; 5, calculating a sublayer characteristic equation bythe step 4; 6, using top face and bottom face displacement of all the sublayers of a laminated shell as an interface to restructure the characteristic equation to solve dynamics response of outputting the laminated structure by the characteristics equation. The laminated shell dynamics analyzing method starts from the laminated shell sublayers to perform independent three-dimensional model construction. At the same time, the influence of lateral shear and contraction deformation is taken into consideration. Besides, various model construction precisions can be achieved according to actual demands, therefore the calculation efficiency is improved, and the calculation cost can also be drastically saved.

Ye Tiangui

Papers

Vibration analysis method of elastic plate structure

Ship acoustic feature intelligent active control method

Vibration analysis method for uniform section beam structure

Laminated shell dynamics analyzing method

Ship structure acoustic radiation characteristic intelligent active control method