Hyperbolic Arch Dam Concrete Constitutive Relations And Damage Identification Research

In recent decades, the development of large-scale hydropower stations is rapid,the great-size structures are most in Southwest and Northwest regions with activeseismic activities, where topographic and geological, hydrological andmeteorological situation is more complex, using sophisticated calculation methodsand test binding actual conditions by King Architectural usage analysis is anessential part in the process of building, such hydropower stations with largeinvestments and long-run cycle are in relation to the national economy and people’slivelihood, after the completion, performance monitoring within normal load and thestudy and work on possibility of damage assessment within unconventional burstloads are being more and more concerned and intentioned, and not limited toresearch areas, but combined with actual engineering, the meaning is far-reachingand significant. To the dynamic analysis of hydraulic concrete structure in largevolume, the research on performance of concrete material, structural resistance,damage identification and selection of damage parameters is incompatible relativelyto the existing hydraulic structural mechanics calculation methods and thedevelopment of the theory, it’s also affect the accuracy of the results of large-volumehydraulic structures, severely restricting further and deeper research on structuraldynamic analysis and the overall reliability and accuracy levels of hydropowerStructural Safety Assessment. The object of this paper is the arch dam, according tothe hydraulic concrete mixture ratio characteristics to develop pilot programs, thenoperate an uniaxial compression testing of concrete subject, analysis concretestress-strain curve of different concrete mix ratio and admixtures, the characteristicsof the compressive strength of concrete, the modulus of elasticity of concrete andthe Poisson’s ratio, based on the summarized analysis of the concrete in static anddynamic failure criterion Research, proposed a two-stage hydraulic concretematerials uniaxial compression quasi-static constitutive model based on The concrete uniaxial compression test results to make a correction to the segment of therise and fall of the stress-strain curve of concrete materials, then proposedconstitutive model based on different mixing ratio and raw concrete uniaxialcompression. For nonlinear finite element analysis of the dam structure, based on theWillam-Warke guidelines and the Haigh-Westerguard coordinate system, afour-parameter criteria as concrete failure criterion is proposed, because differentdam concrete ratio is specially designed with the uniqueness and particularity, so thedata does not match the common concrete material, the criteria parameters aredetermined by the strength of the basic material testing data, this paper presents theguidelines and propagate the corresponding sub-program, structural analysisaccordingly this criteria will work after the entering of concrete strength data, inorder to get the results more consistent with the actual situation. based on concretestatic failure criterion considered variable load such as the temperature field, thewater in the dam and the dam foundation, the preparation of the finite elementanalysis concludes subroutine stack concrete stiffness and mass matrices ImpactFactor, building concrete dynamic analysis equation joined failure and yield criteriafor dam concrete materials, the dynamic finite element analysis of structure canwork, then dong the verification test with the same structure. Analysis hyperbolicarch dam damage, with selection of sensitivity injury indicators appropriate, thefeasibility and reliability of artificial neural network method for dam damageidentification is studied, the study took into account a range of bulk elastic modulusof concrete hardening and the changes of basic access whether brought aboutmisjudgment of damage identification results by the change of the dynamiccharacteristic, the study results show that the artificial neural network can be appliedto the dam structure damage identification, and the method is in higher degreeidentification with the modal parameters such as shapes and the natural vibrationfrequency of structure, and misjudgment is less.