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CN-122021061-A - Method for predicting equivalent uniform load and acting time of non-uniform strong impact load

CN122021061ACN 122021061 ACN122021061 ACN 122021061ACN-122021061-A

Abstract

The invention relates to the technical field of structural power analysis and impact load equivalent calculation, and particularly discloses a method for predicting equivalent uniform load and action time of non-uniform strong impact load, which comprises the following steps of S1, dividing an opposite side fixed supporting member into a plurality of rectangular sheets, and determining pressure peak value and action time of the non-uniform strong impact load at characteristic positions of each sheet; the method comprises the steps of S2, utilizing the pressure peak value and the action time of each piece to calculate the actual work of the non-uniform strong impact load of the area and sum to obtain the total work, S3, utilizing the total work to calculate the equivalent uniform strong impact load, S4, calculating the impulse produced by the non-uniform strong impact load of each piece of area and sum to obtain the total impulse, S5, utilizing the total impulse and the equivalent uniform strong impact load to calculate the equivalent action time, S6, utilizing the equivalent uniform strong impact load and the equivalent action time to establish an equivalent uniform load time history function, and establishing the equivalent uniform load time history function by calculating the total work and the total impulse of the non-uniform strong impact load.

Inventors

  • LIU RUICHAO
  • XU XIANGYUN
  • ZHANG WEIMING
  • YU XIAO

Assignees

  • 中国人民解放军军事科学院国防工程研究院

Dates

Publication Date
20260512
Application Date
20260403

Claims (10)

  1. 1. The method for predicting the equivalent uniform load and the acting time of the non-uniform strong impact load is characterized by comprising the following steps of: S1, acquiring geometric parameters of opposite side fixing and supporting members, dividing the surfaces of the opposite side fixing and supporting members into a plurality of rectangular sheets, and determining pressure peaks and action time of non-uniformly distributed strong impact loads at characteristic positions of the rectangular sheets; S2, calculating real work of the non-uniform strong impact load in each rectangular sheet area by utilizing the pressure peak value and the acting time of the non-uniform strong impact load of each rectangular sheet, and summarizing to obtain total work; s3, calculating equivalent uniform strong impact loads corresponding to the non-uniform strong impact loads by utilizing the total work; s4, calculating impulse generated by non-uniform strong impact load in each rectangular sheet area by utilizing the pressure peak value and the action time of the characteristic position, and summarizing to obtain total impulse; S5, calculating the equivalent acting time of the equivalent uniformly distributed strong impact load by using the total impulse and the equivalent uniformly distributed strong impact load; S6, establishing a time history function of the equivalent uniformly distributed load by utilizing the equivalent uniformly distributed strong impact load and the equivalent acting time.
  2. 2. The method for predicting the equivalent uniform load and the acting time of the non-uniform strong impact load according to claim 1, wherein in S1, the method for determining the feature position of each rectangular sheet is specifically as follows: The surface of the opposite side fixing and supporting component is divided into m sections along the x direction and n sections along the y direction to form m multiplied by n rectangular pieces, and 4 corner points of each rectangular piece are defined as 4 characteristic positions.
  3. 3. The method for predicting equivalent uniform load and action time of non-uniform strong impact load according to claim 1, wherein in S2, the calculation formula of real work of non-uniform strong impact load in rectangular sheet area is: (1); In the formula, The real work of non-uniformly distributed strong impact load on the ith rectangular sheet area is performed, In order to secure the span of the support member to the opposite side, Is the length of the ith rectangular piece in the x direction, Is the y-direction length of the ith rectangular piece, Is the global x-coordinate of the left boundary of the i-th rectangular tile, The length of the ith rectangular piece in the x direction, 、 、 、 The pressure peaks of the non-uniformly distributed strong impact loads at the 4 characteristic positions of the ith rectangular sheet are respectively obtained.
  4. 4. The method for predicting the equivalent uniform load and the acting time of the non-uniform strong impact load according to claim 1, wherein in the step S2, the work calculation of the non-uniform strong impact load is performed by taking the actual acting time of the non-uniform strong impact load as an upper limit.
  5. 5. The method for predicting equivalent uniform load and action time of non-uniform strong impact load according to claim 1, wherein in S3, the calculation formula of equivalent uniform strong impact load is: (2); In the formula, In order to equally distribute strong impact load, The real work of non-uniformly distributed strong impact load on the ith rectangular sheet area is performed, In order to secure the span of the support member to the opposite side, The width of the opposite side fixing support member.
  6. 6. The method for predicting equivalent uniform load and acting time of non-uniform strong impact load according to claim 1, wherein in S4, the calculation formula of impulse generated by the non-uniform strong impact load in each rectangular area is: (3); In the formula, For the impulse on the ith rectangular sheet area, a and b are the side lengths of the rectangular sheet in the x and y directions respectively, 、 、 、 The non-uniform strong impact action time of the four corner points of the ith rectangular sheet is respectively; The pressure peak value of the strong impact load is not uniformly distributed at the characteristic position of the ith rectangular sheet.
  7. 7. The method for predicting equivalent uniform load and action time of non-uniform strong impact load according to claim 1, wherein in S5, the calculation formula of equivalent action time is: (4); In the formula, In order to achieve an equivalent time of action, For the impulse on the ith rectangular plate area, In order to equally distribute strong impact load, In order to secure the span of the support member to the opposite side, The width of the opposite side fixing support member.
  8. 8. The method for predicting equivalent uniform load and action time of non-uniform strong impact load according to claim 1, wherein in S6, the time history function of the equivalent uniform load is a triangle time history function, and the expression is: (5); In the formula, Is an equivalent uniform distribution time-course function of non-uniform strong impact load, In order to equally distribute strong impact load, And t is a time variable, which is equivalent acting time.
  9. 9. The method for predicting equivalent uniform load and action time of non-uniform strong impact load according to claim 8, wherein the triangular time course function is consistent with the time course form of the original non-uniform strong impact load in terms of duration and pressure peak value.
  10. 10. The method for predicting the equivalent uniform load and the acting time of the non-uniform strong impact load according to claim 1, wherein the method for predicting the equivalent uniform load and the acting time is suitable for the equivalent calculation of the non-uniform strong impact load with asymmetric spatial distribution and local concentration.

Description

Method for predicting equivalent uniform load and acting time of non-uniform strong impact load Technical Field The invention relates to the technical field of structural power analysis and impact load equivalent calculation, in particular to a prediction method of equivalent uniform load and action time of non-uniform strong impact load. Background The strong impact load has the advantages of high acting strength, short duration time and complex spatial distribution, and has decisive influence on the impact resistance and the building stability of the components. In engineering dynamic analysis, especially when an equivalent single degree of freedom (SDOF) method is used to rapidly evaluate a structure, a true complex load form is usually required to be converted into an equivalent uniform load for calculation. The method is characterized in that the non-uniform strong impact load is reasonably and accurately equivalent to the uniform load and the acting time thereof, which are the precondition that the equivalent single-degree-of-freedom prediction method is established, and the reliability of the structural dynamic response prediction result and the safety of engineering design are directly related, so that the method has important engineering significance and research value. However, the existing research on the equivalent uniform load of the non-uniform load still has a plurality of defects. Firstly, the existing method is mainly only suitable for the situation of non-uniform load which is symmetrically distributed in space, has obvious symmetry in spite of non-uniform distribution in form, and in actual engineering, strong impact load is often represented as obvious asymmetric and locally concentrated distribution characteristics, and real uniform distribution or symmetrical distribution is rather ideal, so that the engineering applicability of the existing method is limited. Secondly, the existing research hardly performs strict equivalence on the load acting time, and usually only selects the acting time or impulse as an input parameter in an experience or reliable interval, and does not perform systematic calculation from the energy or impulse angle, which introduces a large calculation error in the power response problem with high sensitivity to the load acting time. Again, while some methods use consistent work as an equivalent criterion, their calculation often assumes that the component has responded to a maximum displacement condition, at which point the load may have been removed, which assumption is severely inconsistent with the true load application process. In addition, the existing method for equally distributing the load by non-uniformly distributing the load is generally assumed to be a constant rectangular load form on the load time course, is inconsistent with the more common triangular or nonlinear time course load in the actual engineering, and can further amplify the equivalent error and reduce the reliability of the calculation result on the premise that the space distribution is already equivalent. In summary, the existing prediction method for the non-uniform strong impact load to the equivalent uniform load has obvious defects in the aspects of space distribution applicability, load acting time equivalence, real acting calculation, load time course expression and the like, and is difficult to meet the requirement for fine prediction of dynamic response under complex engineering conditions. Therefore, a prediction method capable of simultaneously and accurately equivalent non-uniformly distributing strong impact load space distribution, real acting, impulse and acting time and keeping consistency of load time course forms is established, and has important significance for improving accuracy and engineering applicability of the equivalent single-degree-of-freedom analysis method. Disclosure of Invention The invention aims to provide a prediction method of equivalent uniform load and action time of non-uniform strong impact load, which is used for determining the equivalent uniform strong impact load and equivalent action time by calculating the total acting and total impulse of the non-uniform strong impact load and establishing a time history function of the equivalent uniform load. In order to achieve the above purpose, the present invention provides the following technical solutions: a prediction method for equivalent uniform load and action time of non-uniform strong impact load comprises the following steps: S1, acquiring geometric parameters of opposite side fixing and supporting members, dividing the surfaces of the opposite side fixing and supporting members into a plurality of rectangular sheets, and determining pressure peaks and action time of non-uniformly distributed strong impact loads at characteristic positions of the rectangular sheets; S2, calculating real work of the non-uniform strong impact load in each rectangular sheet area by utilizing the pressure peak v