Method for eliminating thermal buckling of lattice sandwich panel structure and restraining nonlinear flutter

A sandwich panel and nonlinear technology, which is applied in the field of eliminating thermal buckling of lattice sandwich panel structures and suppressing nonlinear flutter, can solve the problems of structural natural frequency changes, active stiffness cannot fully compensate for temperature changes, etc., and achieve design saving The effect of installation time

Inactive Publication Date: 2020-09-29
HARBIN ENG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] The purpose of the present invention is to solve the problem that existing piezoelectric materials are often used in the control of structural flutter and thermal buckling, and the active stiffness cannot fully compensate ...

Method used

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  • Method for eliminating thermal buckling of lattice sandwich panel structure and restraining nonlinear flutter
  • Method for eliminating thermal buckling of lattice sandwich panel structure and restraining nonlinear flutter
  • Method for eliminating thermal buckling of lattice sandwich panel structure and restraining nonlinear flutter

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specific Embodiment approach 1

[0022] Embodiment 1: A method for eliminating thermal buckling of a lattice sandwich panel structure and suppressing nonlinear flutter described in this embodiment includes the following steps:

[0023] Step 1: Establish the strain-displacement relationship and constitutive relationship of the lattice sandwich panel structure based on the geometric deformation of the lattice sandwich panel structure;

[0024] Step 2: Establish the expressions of the supersonic aerodynamic force and the work done by the in-plane thermal load and the mathematical model of the elastic foundation structure, obtain the expressions of the kinetic energy, deformation energy and elastic foundation potential energy of the lattice sandwich panel, and establish points based on the Hamilton variational principle The aerodynamic thermoelastic motion equation of the array sandwich panel structure;

[0025] Step 3: Solve the aerothermoelastic motion equation of the lattice sandwich panel structure based on t...

specific Embodiment approach 2

[0026] Specific implementation mode two: the detailed steps of described step one are:

[0027] Step ①: Establish the expression of the displacement field of the lattice sandwich panel structure:

[0028] w (p) =w,p=1,2;

[0029] u (3) =u-zθ x , v (3) =v-zθ y ,w (3) = w;

[0030] The superscript "p" represents the upper panel and the lower panel of the lattice sandwich panel structure, 1 is the upper panel of the lattice sandwich panel structure, and 2 is the lower panel of the lattice sandwich panel structure; the superscript "3" represents the lattice sandwich panel core plate structure core; h c is the thickness of the core; u, v and w are the displacements of the structural neutral plane along the x, y and z axes respectively; θ x and θ y represent the rotation angles of the neutral plane along the y and x axes, respectively;

[0031] Step ②: Establish the expression of the strain-displacement relationship of the lattice sandwich panel structure through the ex...

specific Embodiment approach 3

[0046] Specific implementation mode three: the core equivalent shear modulus G in the step 3. c The expression is:

[0047]

[0048] Among them, ρ r is the relative density of the core, Ec is the elastic modulus of the pyramid core material, α c is the inclination angle of the pyramid lattice rod;

[0049] where ρ r The expression is:

[0050]

[0051] where l c is the length of the pyramid lattice rod; α c is the inclination angle of the pyramid lattice rod; r c is the radius of the pyramid lattice rod.

[0052] Other steps and parameters are the same as those in Embodiment 1 or Embodiment 2.

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Abstract

The invention discloses a method for eliminating thermal buckling of a lattice sandwich panel structure and restraining nonlinear flutter. The invention aims to solve the problems that an existing piezoelectric material is often used for controlling flutter and thermal buckling of a structure, the influence caused by temperature change cannot be completely compensated by active rigidity, and the change of the inherent frequency of the structure is also caused. The method comprises the following steps: establishing a strain-displacement relationship and a constitutive relationship of a latticesandwich panel structure; establishing expressions of work done by supersonic aerodynamic force and in-plane thermal load and a mathematical model of the elastic foundation structure, obtaining expressions of kinetic energy, deformation energy and elastic foundation potential energy of the dot matrix sandwich panel, and establishing an aerodynamic thermal elastic motion equation of the dot matrixsandwich panel structure; based on a four-order Runge-Kutta method, solving an aerodynamic thermoelastic motion equation of the lattice sandwich panel structure, and performing analyzing to obtain aninfluence rule of an elastic foundation on aerodynamic thermoelastic characteristics of the lattice sandwich panel structure. The invention belongs to the field of aerospace.

Description

technical field [0001] The invention relates to a method for eliminating thermal buckling of a lattice sandwich panel structure and suppressing nonlinear flutter. Background technique [0002] The lattice sandwich structure is a new type of laminated material structure, which has excellent characteristics such as light weight, high specific strength, high specific stiffness, noise reduction and heat insulation, and is extremely suitable for the design of future aircraft structures. Since aircraft structures are often placed on elastic media such as thermal protection layers or damping strips, elastic media have a great influence on the aerothermoelastic properties of lattice sandwich structures. Therefore, it is of great significance to study the aerothermoelasticity of elastic basic lattice sandwich structures in supersonic airflow. In addition, in order to further improve the reliability of future hypersonic vehicles, so that they can fly stably and safely in complex envi...

Claims

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Application Information

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IPC IPC(8): G06F30/15G06F30/20G16C60/00G06F111/10G06F113/26G06F119/08
CPCG06F30/15G06F30/20G16C60/00G06F2113/26G06F2119/08G06F2111/10Y02T90/00
Inventor 柴玉阳李凤明宋智广
Owner HARBIN ENG UNIV
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