Bridge inspection and evaluation method based on impact vibration

Patent metadata

Field	Value
Publication number	US-10620085-B2
Application number	US-201615570339-A
Country	US
Kind code	B2
Filing date	Aug 26, 2016
Priority date	Jun 30, 2016
Publication date	Apr 14, 2020
Grant date	Apr 14, 2020

Abstract

The present invention discloses a bridge inspection and evaluation method based on impact vibration. The method includes backward analysis of the bridge based on impact on blocks without reference points and forward analysis of the bridge based on progressive impact loading, where the backward analysis of the bridge based on impact on blocks without reference points is used to rapidly inspect the medium and small bridges from the road network to find the ones with serious shortage of bearing capacity, and the forward analysis of the bridge based on progressive impact loading is used to evaluate the actual bearing capacity of the bridges, which may have good safety condition in the backward analysis. The present invention realizes low-cost and highly efficient inspection and evaluation of the medium and small bridges in the road network.

First claim

What is claimed is:

1. A bridge inspection and evaluation method based on impact vibration, comprising:
performing backward analysis of a bridge based on impact on divided blocks without reference points and forward analysis of a bridge based on progressive impact loading,

wherein the backward analysis of the bridge based on impact on divided blocks without reference points is used to rapidly inspect medium and small bridges from a road network to find bridges with serious shortage of bearing capacity, and the forward analysis of the bridge based on progressive impact loading is used to evaluate an actual bearing capacity of bridges, in good safety condition according to the backward analysis;
wherein a flexibility identification method of an overall structure of the bridge based on impact on divided blocks without reference points is used in the backward analysis of the bridge, and specifically comprises:
estimating a frequency response function of a sub-block of the overall structure, identifying modal parameters of the sub-block, scaling modal shape of the sub-block,
determining a direction of the modal shape of the sub-block, and calculating a flexibility matrix of the overall structure.

2. The bridge inspection and evaluation method based on impact vibration according to claim 1 , wherein an impact test on blocks without reference points is used in the backward analysis of the bridge based on impact on blocks without reference points, and specifically comprises:
dividing the overall structure of the bridge into several sub-blocks, wherein locations of impact points and measurement points in different sub-blocks are selected independently,
performing point-by-point impact on impact points in each of the sub-blocks, and at the same time receiving impact force time-history data of each of the sub-blocks and acceleration time-history data of measurement points.

3. The bridge inspection and evaluation method based on impact vibration according to claim 1 , wherein in the flexibility identification method of the overall structure based on impact on blocks without reference points,
during the modal shape scaling of the sub-block, a scaling degree of the modal shape of a sub-block S 1 is used as a standard to perform the modal shape scaling on all sub-blocks of the overall structure, and the formula is:

{

ϕ
~

r

S
k

}

=

η
r

S
k

⁢

Q
r

S
k

Q
r

S
1

⁢

{

ϕ
r

S
k

}

,

where {ϕ r S k } and {{tilde over (ϕ)} r S k } are respectively r th modal shapes of sub-block S k before and after the modal shape scaling, ϕ r S k is scaling coefficient of the r th modal shape of the sub-block S k before the modal shape scaling, ϕ r S 1 is scaling coefficient of the r th modal shape of the sub-block S 1 , and η r S k is direction coefficient of the r th modal shape of the sub-block S k (η r S k =+1 or η r S k =−1);
and subsequently, the scaled modal shapes of all the sub-blocks S 1 , S 2 , . . . , S k , . . . , and S n are integrated into a modal shape of the overall structure of the bridge, and the formula is:

{

ϕ
~

r

}

=

⁢

(

{

ϕ
~

r

S
1

}

T

⁢

⁢

{

ϕ
~

r

S
2

}

T

⁢

⁢
⋯
⁢

⁢

{

ϕ
~

r

S
k

}

T

⁢

⁢
⋯
⁢

⁢

{

Assignees

• Univ Southeast

Inventors

• Zhang Jian
• Xia Qi
• Zhang Bo
• Guo Shuanglin

Classifications

• G01M7/08 Primary

  Shock-testing · CPC title

• G01H1/14

  Frequency · CPC title

• G01M5/0008

  of bridges · CPC title

• G01M5/0066

  by exciting or detecting vibration or acceleration (vibration testing of structures G01M7/00) · CPC title

• G01H1/00

  Measuring {characteristics of} vibrations in solids by using direct conduction to the detector (G01H9/00, G01H11/00 take precedence) · CPC title