Method for simulating temperature cracking value of mass concrete

Abstract

The invention discloses a method for simulating the temperature cracking value of mass concrete. The method comprises the following steps of: I, establishing a physical model of concrete, wherein the physical model consists of aggregate and mortar; II, dispersing the physical model obtained in the step I into a series of physical units; III, inserting thickness interface units among the physical model units obtained in the step II to form a concrete mesoscopic model; IV, simulating the temperature field of concrete; and V, simulating the mesoscopic cracking process of the concrete model under the temperature field in the step IV by adopting a continuous-discrete coupling method. In the method, the shape and gradation of aggregate particles and the random distribution condition of the aggregate particles in a calculating domain are fully considered, so that the microstructure of concrete can be simulated more really, the generation, expansion and penetration of cracks in the mass concrete can be simulated more really, and an entire process ranging from small deformation to large deformation till destroy of a concrete material can be reflected.

Description

technical field [0001] The invention belongs to the field of water conservancy and hydropower engineering, and in particular relates to a numerical simulation method for temperature cracking of large-volume concrete. Background technique [0002] With the construction of many 300m high arch dams in China in recent years, the problem of temperature cracks in mass concrete has become increasingly prominent, and the problem of temperature crack control in mass concrete has become the focus of attention and discussion in the academic circles. During the construction and operation of concrete dams, large-volume concrete structures often produce large tensile stress due to temperature changes, so cracks often appear in mass concrete structures. If it is a surface crack, it will cause damage to the durability of the concrete. If it develops into a deep or penetrating crack, it will affect the integrity of the concrete structure, change the stress distribution and stress conditions ...

AI Technical Summary

Problems solved by technology

Concrete cracking is essentially a process of micro-crack initiation, expansion, penetration, and overall instability. It is a gradual evolution-induced catastrophe process from micro-damage evolution to macro-cracking. Therefore, it cannot truly reflect concrete from a macro perspective. The multi-phase composite composition and the heterogeneous characteristics of the material cannot reflect the existence, expansion, extension and penetration process of micro-cracks.

At present, domestic and foreign scholars' research on temperature cracking is mainly based on the macroscopic level. Concrete is regarded as a single-average material to study, which cannot truly reflect the mesoscopic structure of concrete, and naturally it is impossible to obtain the real temperature cracking behavior.

Very few scholars have carried out research on the mesostructure of concrete. Generally, the stochastic mechanical property model is used to consider the randomness of the distribution of the mechanical properties of each phase component of concrete, but they fail to consider the shape, gradation, and distribution of aggregate particles in the computational domain. random distribution, and are limited to the study of small-sized concrete specimens

However, in terms of the mesoscopic cracking mechanism and dynamic expansion simulation method of mass concrete temperature cracks, there are no relevant research results at home and abroad.

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