Patent ID: 11946213
Assignee: SOUTHWEST JIAOTONG UNIVERSITY
Field: Civil engineering (Other fields)
Classification: CPC E  Y | IPC E

Claim 0:
1. A structural design method for a high-speed train derailment arresting system, wherein high-speed train derailment arresting system comprises a plurality of passive protection arresting devices arranged on both sides of a high-speed railway line, each of the plurality of passive protection arresting devices comprises a rigid support assembly fixed to a respective side of the high-speed railway line, and a rotating protective barrel arranged on the rigid support assembly; the rigid support assembly comprises cross beams, clamps, and an upright post fixed to the respective side of the high-speed railway line, the rotating protective barrel is sleeved on the upright post and supported by the cross beams, and the cross beams are fixed to the upright post through the clamps; and the rotating protective barrel comprises a stainless-steel inner shell and a stainless-steel outer shell, and a foam energy-absorbing layer is arranged between the stainless-steel inner shell and the stainless-steel outer shell;
the structural design method comprising:
Step S1, calculating initial kinetic energy of a train, and listing an energy conservation equation of structures participating in energy absorption according to energy conservation;
wherein in the Step S1, the energy conservation equation of the structures participating in energy absorption is obtained as follows:, E
   
    t
    ⁢
    o
    ⁢
    t
    ⁢
    a
    ⁢
    l
   
  
  =
  
   
    
     1
     2
    
    ⁢
    
     mv
     1
     2
    
   
   =
   
    
     E
     
      p
      ⁢
      o
      ⁢
      s
      ⁢
      t
     
    
    +
    
     E
     
      b
      ⁢
      a
      ⁢
      r
      ⁢
      r
      ⁢
      e
      ⁢
      l
     
    
    +
    
     E
     1
    
    +
    
     E
     2
    
    +
    
     E
     3
    
    +
    
     
      1
      2
     
     ⁢
     
      mv
      2
      2
     
    
   
  
 

wherein m is a mass of the train, v1 is a speed before a collision between the train and the high-speed train derailment arresting system, Epost is a sum of energy absorbed by all upright posts, Ebarrel is a sum of energy absorbed by all rotating protective barrels, E1 is a friction work between the train and a ground, E2 is energy absorbed by train deformation, E3 comprises a friction work between the rotating protective barrels and the upright posts, the slewing rings and the train, a friction work between the slewing rings and the cross beams, the clamps and the upright posts, and energy absorbed by the cross beams, the clamps, the bolts, the nuts and the slewing rings, and v2 is a speed of the train when the high-speed train derailment arresting system completes a guiding effect on the train;
Step S2, setting an energy conversion rate that the high-speed train derailment arresting system needs to reach, simplifying the energy conservation equation of the Step S1 and preliminarily determining an energy absorption ratio of upright posts to rotating protective barrels, thereby determining an amount of energy absorbed by the upright posts and energy absorbed by the rotating protective barrels;
wherein in the Step S2, the energy conversion rate that the high-speed train derailment arresting system needs to reach is set, the energy conservation equation in the Step S1 is simplified, the friction work E1 between the train and the ground, the energy E2 absorbed by train deformation, E3 which comprises the friction work between the rotating protective barrels and the upright posts, the slewing rings and train, the friction work between the slewing rings and the cross beams, the clamps and the upright posts, and the energy absorbed by the cross beams, the clamps, the bolts, the nuts and the slewing rings are ignored, thus an energy equation is obtained as follows:, E
    4
   
   =
   
    
     
      E
      
       p
       ⁢
       o
       ⁢
       s
       ⁢
       t
      
     
     +
     
      E
      
       b
       ⁢
       a
       ⁢
       r
       ⁢
       r
       ⁢
       e
       ⁢
       l
      
     
    
    =
    
     
      1
      2
     
     ⁢
     
      
       mv
       1
       2
      
      (
      
       1
       -
       k
      
      )
     
    
   
  
  ;
 

wherein k is the energy conversion rate, and, k
   =
   
    
     
      1
      2
     
     ⁢
     m
     ⁢
     
      v
      2
      2
     
    
    
     
      1
      2
     
     ⁢
     m
     ⁢
     
      v
      1
      2
     
    
   
  
  ;, and
wherein in the Step S2, assuming that the sum of energy absorbed by all upright posts accounts for β of E4, the energy absorbed by the upright posts and the energy absorbed by the rotating protective barrels are determined as follows:, E
   
    p
    ⁢
    o
    ⁢
    s
    ⁢
    t
   
  
  =
  
   
    β
    ⁢
    
     E
     4
    
   
   =
   
    
     1
     2
    
    ⁢
    β
    ⁢
    
     
      mv
      1
      2
     
     (
     
      1
      -
      k
     
     ), E
    barrel
   
   =
   
    
     
      (
      
       1
       -
       β
      
      )
     
     ⁢
     
      E
      4
     
    
    =
    
     
      1
      2
     
     ⁢
     
      (
      
       1
       -
       β
      
      )
     
     ⁢
     
      
       mv
       1
       2
      
      (
      
       1
       -
       k
      
      )
     
    
   
  
  ;
 

Step S3, estimating a number of the upright posts and a number of the rotating protective barrels participating in the energy absorption, further determining an average energy absorption value of the upright posts and an average energy absorption value of the rotating protective barrels, respectively, and designing a single upright post and a single rotating protective barrel according to the average energy absorption value of the upright posts and the average energy absorption value of the rotating protective barrels;
wherein in the Step S3, estimating the number of the upright posts and the number of the rotating protective barrels participating in the energy absorption is obtained specifically as follows:, n
   ≈
   
    c
    f
   
  
  ;
 

wherein c is a length of a portion of the high-speed train derailment arresting system that interacts with the train in a period from the train comes into contact with the high-speed train derailment arresting system until the high-speed train derailment arresting system completes a guiding effect on the train, f is a spacing between adjacent upright posts of the upright posts, and n is an integer;
wherein in the Step S3, a method for respectively determining the average energy absorption value of the upright posts and the average energy absorption value of the rotation protective barrels is obtained as follows:, E
   
    post
    ⁢
      
    x
   
  
  =
  
   
    
     E
     
      p
      ⁢
      o
      ⁢
      s
      ⁢
      t
     
    
    n
   
   =
   
    
     
      E
      
       post
       ⁢
         
       1
      
     
     +
     
      E
      
       post
       ⁢
         
       2
      
     
     +
     
      E
      
       post
       ⁢
         
       3
      
     
     +
     …
     +
     
      E
      
       post
       ⁢
         
       n
      
     
    
    n
   
  
 

 
  
   
    E
    
     b
     ⁢
     a
     ⁢
     r
     ⁢
     r
     ⁢
     e
     ⁢
     l
     ⁢
     y
    
   
   =
   
    
     
      E
      
       b
       ⁢
       a
       ⁢
       r
       ⁢
       r
       ⁢
       e
       ⁢
       l
      
     
     n
    
    =
    
     
      
       E
       
        b
        ⁢
        a
        ⁢
        rrel
        ⁢
          
        1
       
      
      +
      
       E
       
        b
        ⁢
        a
        ⁢
        rrel
        ⁢
          
        2
       
      
      +
      
       E
       
        b
        ⁢
        a
        ⁢
        rrel
        ⁢
          
        3
       
      
      +
      …
      +
      
       E
       
        b
        ⁢
        a
        ⁢
        rrel
        ⁢
          
        n
       
      
     
     n
    
   
  
  ;
 

wherein Epost n is energy absorbed by a n-th deformed upright post of the upright posts, and Ebarrel n is energy absorbed by a n-th deformed rotating protective barrel of the rotating protective barrels;
as the stainless-steel outer shell mainly plays a protective role on the foam energy-absorbing layer, a thickness of a stainless-steel layer of the stainless-steel outer shell in a preliminary design is low; and in order to simplify calculation, an energy absorption effect of the stainless-steel outer shell is ignored, and only energy absorption Eabsorption y of the foam energy-absorbing layer is considered, that is:

Eabsorption y=Ebarrel y 

Step S4, according to a height of a train body of the train and a height from a nose tip of a high-speed train head to the ground, preliminarily setting a height of the upright posts while considering to reserve a design space for the rotating protective barrels, setting a transverse dynamic deformation value of the upright posts, calculating a rotation angle of a supporting hinge point of the upright posts, and listing a bending energy balance equation of the upright posts based on a Parkes model, thereby calculating a diameter of the upright posts, wherein the height of the upright posts comprises a height above the ground and an embedded height of the upright posts in concrete foundation;
wherein in the Step S4, a bending energy balance equation of the upright post listed based on the Parkes model is obtained as follows:, E
    
     post
     ⁢
       
     x
    
   
   =
   
    
     
      M
      u
     
     ⁢
     θ
    
    =
    
     
      
       σ
       s
      
      ⁢
      
       W
       s
      
      ⁢
      θ
     
     =
     
      
       
        σ
        s
       
       ⁢
       α
       ⁢
       
        W
        z
       
       ⁢
       θ
      
      =
      
       
        σ
        s
       
       ⁢
       α
       ⁢
       
        
         π
         ⁢
         
          D
          post
          3
         
        
        
         3
         ⁢
         2
        
       
       ⁢
       θ
      
     
    
   
  
  ;
 

wherein Mu is an ultimate bending moment, θ is a rotation angle of the supporting hinge point, σs is yield strength of a material, Ws is a plastic bending section coefficient, Wz is a bending section coefficient, wherein the bending section coefficient of a circular section is, W
    z
   
   =
   
    
     π
     ⁢
     
      D
      post
      3
     
    
    
     3
     ⁢
     2
    
   
  
  ,, α is a section shape coefficient, the section shape coefficient of the circular section is, α
   =
   
    
     1
     ⁢
     6
    
    
     3
     ⁢
     π
    
   
  
  ,, and Dpost is the diameter of the upright posts;
a method for calculating the rotation angle of the supporting hinge point is obtained as follows:, θ
   ≈
   
    
     πarcsin
     ⁡
     (
     
      P
      
       l
       1
      
     
     )
    
    
     180
     ⁢
     °
    
   
  
  ;
 

wherein P is a transverse dynamic deformation value of the upright posts that is a transverse horizontal displacement of the upright posts relative to an initial position after bending deformation, and l1 is the height of the upright posts above the ground; and
wherein in the Step S4, a method for calculating the diameter of the upright posts is, D
   
    p
    ⁢
    o
    ⁢
    s
    ⁢
    t
   
  
  =
  
   
    
     3
     ⁢
     β
     ⁢
     
      
       fmv
       1
       2
      
      (
      
       1
       -
       k
      
      )
     
    
    
     
      σ
      s
     
     ⁢
     c
     ⁢
     
      
       π
       ⁢
       arcsin
       ⁢
       
        (
        
         P
         
          l
          1
         
        
        )
       
      
      
       180
       ⁢
       °
      
     
    
   
   3
  
 

Step S5, according to a height from the nose tip of the high-speed train head of an electric multiple unit (EMU) to the ground, ensuring that the nose tip of the high-speed train head and a center of each of the rotating protective barrels are in a same horizontal plane, and preliminarily determining a height from the center of the each of the rotating protective barrels to the ground; preliminarily setting a height of the foam energy-absorbing layer according to a front end structure of the high-speed train head, and obtaining average energy absorption value of the foam energy-absorbing layer per unit volume according to a stress-strain curve integral of a foam material, calculating an outer diameter of the foam energy-absorbing layer from the average energy absorption value of the foam energy-absorbing layer and the average energy absorption value of the rotating protective barrel in the Step S3 through a simultaneous equation, and correcting a value of the outer diameter of the foam energy-absorbing layer;
wherein in the Step S5, a method for calculating the outer diameter of the foam energy-absorbing layer is as follows:
the average energy absorption of the foam material per unit volume of the foam energy-absorbing layer is obtained as follows:, e
    f
   
   =
   
    
     ∫
     
       
      0
     
     
       
      
       ε
       p
      
     
    
    
     σ
     ⁢
     d
     ⁢
     ε
    
   
  
  ;
 

wherein ε is strain, σ is stress, and εp is average strain of the foam material of the foam energy-absorbing layer;
the volume of the foam energy-absorbing layer is obtained as follows:, V
   absorption
  
  =
  
   
    E
    
     absorption
     ⁢
       
     y
    
   
   
    e
    f
   
  
 

 
  
   
    V
    absorption
   
   =
   
    
     π
     [
     
      
       
        (
        
         
          D
          absorption
         
         2
        
        )
       
       2
      
      -
      
       
        (
        
         
          d
          absorption
         
         2
        
        )
       
       2
      
     
     ]
    
    ⁢
    
     L
     absorption
    
   
  
  ;, wherein Dabsorption is the outer diameter of the foam energy-absorbing layer, dabsorption is an inner diameter of the foam energy-absorbing layer, and Labsorption is a height of the foam energy-absorbing layer,
thus, the outer diameter Dabsorption of the foam energy-absorbing layer is obtained as follows:, D
    absorption
   
   =
   
    2
    ⁢
    
     
      
       
        
         (
         
          1
          -
          β
         
         )
        
        ⁢
        f
        ⁢
        m
        ⁢
        
         
          v
          1
          2
         
         (
         
          1
          -
          k
         
         )
        
       
       
        2
        ⁢
        π
        ⁢
        c
        ⁢
        
         e
         f
        
        ⁢
        
         L
         
          a
          ⁢
          b
          ⁢
          s
          ⁢
          o
          ⁢
          r
          ⁢
          p
          ⁢
          t
          ⁢
          i
          ⁢
          o
          ⁢
          n
         
        
       
      
      +
      
       
        (
        
         
          d
          
           a
           ⁢
           b
           ⁢
           s
           ⁢
           o
           ⁢
           r
           ⁢
           p
           ⁢
           t
           ⁢
           i
           ⁢
           o
           ⁢
           n
          
         
         2
        
        )
       
       2
      
     
    
   
  
  ;
 

Step S6, properly selecting a dimension of the cross beams, a dimension of the clamps, a dimension of slewing rings, a dimension of bolts and a dimension of nuts as long as structural and functional requirements are satisfied.