The Research On Strain Rate Effect Of Dynamic Behaviors Ofreinforced Concrete Remembers

Concrete is a typical strain rate-sensitive materials with different strain rate thestrength, ductility and failure mode has changed significantly. Civil Engineeringsare inevitable to meet the effect of dynamic load in addition to the various concretestructures to withstand static loading. In conclusion, the European ConcreteAssociation CEB, on the basis of the majority of test results, provides a quasi-staticstrain rate, recommended a different strain rate dynamic compressive strength ofconcrete materials, peak strain, elasticity modulus relative quasi-static strain rateincrease factor. Thus for a certain range of strain rate to a thorough study of thedynamic constitutive relationship of concrete materials and failure criteria atdifferent strain rates is necessary.We first have done a pilot study on beam mode materials dynamic modulus,abtained by the inverse the natural frequencies, such as beam component. Derivedthe structural materials elasticity modulus and strain rate expression of thecross-section of the beam components of the three-point bending beam., through thethree-point bending beam test device we make three-point bending concrete beamvibration test, The results show that with the growth of the strain rate across thetwo groups the beam dynamic modulus have differently raise and further get thecoefficiert expression of the concrete elastic modulus by fitting the test resultsconsidering the strain rate effect.Take into account the response characteristics of the concrete structure underearthquake, we make uni-directional dynamic compression test of concrete columnand concrete columns by sodium erosioned, a comprehensive study the strain rateeffect on the concrete strength and deformation characteristics, and analysis aboutthe intensity, elastic modulus, peak strain and energy absorption capabilitycharacteristics under the different strain rates, The results showed that the strength,peak strain and energy absorption characteristics of the concrete columns with thestrain rate increased have significantly increased at different strain rates, the elasticmodulus did not change significantly, and the above properties at different strainrate of the corrosion concrete columns are lower than the correspondingcharacteristics of concrete columns which is not corrosioned. And futher discuss thefailure mechanism at the different strain rates, and study the stress-strain curves under the different strain rates, amending them based on the static constitutivemodel to become dynamic constitutive model.Using this expression and the combination of component fiber cross-section ofthe layered model of reinforced concrete beam and columns to numerical analysisof the moment-curvature, yield moment, yield curvature, ultimate moment ultimatecurvature under the different strain rates.