The Improvement Of Numerical Model On Concrete Meso-Mechanics And The Study Of Its Dynamic Properties

In this paper,the concrete specimen performance of distortion, damage and failure under the static and dynamic effection were analyzed in the method combined the damage-mechanica and computational mechanics based on the meso-mechanics .the elastic damage constitutive and the equivalent viscoelastic constitutive were used. the static and dynamic performances of concrete on meso-mechanics and the factors which influenced the strength and distortion of concrete on meso-mechanics were studied by means of the software—ANSYS developed secondly . Main works of this paper include:1. A new math model and program of 3-D random aggregate model of concrete is established. In the model the concrete was treated as component materials composed by cement mortar, araggregate and interface between them, aggregate sphere space locations were generated randomly and the interface was stimulated by the contact elements ,the programs on them were made.the scarcities of the old model such as the great thickness of the interface ,the great number of element after the mesh refined and the low reliability of the results were overcomed.the new model was more similar to the real model ,and the speed of compute was enhanced.2. By the means of meso damage theory,the size effection of meso concrete was researched .the size ratio of concrete specimen and the aggregate influences the strength ,and the effection should be concerned.the concrete would appear asymmetric distortion and stress,when it was effected by the crescent loads.its appearance was as a result of the asymmetry of the concrete materials.with the same mix proportion , the random location of aggregate and the aggregate and specimen radius ratio were changed to research their influenction on the strength and distortion of the specimen.3. Under the impact and sine loads,the dynamic properties of the model established was computed.the changes of displacement and strength of the specimen under different loads were researched.in the computation of impact, the load rate was changed to research the changes of the location and number of cracking parameter nodes.the influences of the dynamic properties due to the load rate were researched.In this paper ,the concrete effected by ststic and dynamic loads were meso numerically simulated ,the concrete properties of static and dynamic meso-mechanical performance were researched.