Numerical Simulation Of Freezing Temperature Field And Reliability Analisis Of Frozen Wall

In recent years,as the freezing method is more and more widely used in engineering,the practical value of the freezing method research has become higher and higher.As one of the core problems in the application of the freezing method,the study of the distribution law of the freezing temperature field has not achieved a great breakthrough.At present,the research on the freezing temperature field is still focused on the two directions.One direction is about case analysis,the other direction is about deterministic analysis.The advantage of case analysis is that it can effectively solve the specific problems,its shortcoming is that there are few universally applicable conclusions appearing.Research in the direction of deterministic analysis has the advantage of simplifying real problems,so that it can provide solutions for real problems.The disadvantage is that the complexity and randomness of real problems are not fully considered.The results of studies are often quite different from the actual ones.Aiming at the existing problems,this paper is based on the theory and method of finite element analysis,combined with the concept and theory of structural reliability analysis,explored the general conclusions of the freezing temperature field,and established a reliability analysis system of the freezing temperature field,so as to promote the transition of freezing temperature field research from deterministic analysis to reliability analysis.The main research contents of this article are as follows:(1)Most of the existing analytical formulas for steady-state temperature fields contain hidden parameters,and in practical engineering applications,hidden parameters are often difficult to know.This contradiction leads to the poor practicality of existing analytical solutions in engineering.In order to solve this problem,this paper uses a large number of numerical simulations to explore the relationship between implicit parameters and explicit parameters,and uses two methods of least squares and partial least squares to fit the relationship between implicit parameters and explicit parameters.Explicit parameters are used to replace implicit parameters to achieve the transformation of existing formulas,making them more practical on engineering practice applications;(2)Existing finite element software often can only perform deterministic calculations and analysis.To solve this problem,this paper is based on the basic principles of the finite element solution of the transient heat conduction partial differential equation combined with the basic theory of random fields,and derives compiled formulas and programs for numerical simulation of transient temperature fields.Based on the determination of the temperature field,combined with engineering examples,the calculation and analysis of random temperature fields are achieved,and a series of distribution laws of random temperature fields are obtained,which are compared and analyzed with the determined temperature field;(3)The reliability analysis of the freezing temperature field is still in its infancy,and there are few existing limit state function of frozen walls.In response to this problem,this paper defines the limit state of the frozen wall from two perspectives of strength and deformation,establishes two sets of independent frozen wall functions,and derives and writes calculation formulas and procedures for the frozen wall failure probability,so as to establish the reliability analysis method of the freezing temperature field.Combined with the results of the transient random temperature field which has been simulated,this paper calculates the calculation of examples and performs the parameter analysis of the reliability of the frozen wall.