Research On Criterion Of Ultimate Bearing Capacity Of Reinforced Concrete Members Based On Probability And Statistics Analysis

The reinforced concrete simply supported beam is a typical concrete component that is widely used in the engineering structure.Its bearing capacity must meet the design requirements to ensure sufficient safety and stability.The ultimate bearing capacity plays an important role in the design,strengthen and safety evaluation of the concrete structure.Probabilistic statistical analysis has objective meaning and has great advantages in analyzing data,by using the theory of probability statistics,we can analyze the laws presented by the data as a whole.At present,there are few researches on the criteria for the analysis of ultimate bearing capacity of reinforced concrete members based on probability statistics.In this paper,the author studied the ultimate bearing capacity criterion of reinforced concrete members and the failure of components.First the authorthe used the finite element analysis software to simulate the beams,and then counted the variation of each physical quantity(element strain energy,stress,strain,etc.)during the loading process.The destruction of beams is studied by analyzing the changing trend of the strain energy and the first principal strain of the concrete element.The criterion of ultimate bearing capacity of concrete members was discussed,and experimental verification was also carried out.The specific research contents are as follows:(1)According to the variation law of the elastic strain energy of the concrete element in the loading process of the simply supported beam,the author proposed the criterion of the ultimate bearing capacity based on the elastic strain energy.And the reliability and applicability of the strain energy criterion under different modeling parameters and different load types is also discussed.The study found that the strain energy of the concrete element conforms to the lognormal distribution,and the ultimate capacity of the component can be determined by the change of the logarithmic normal distribution parameter of the strain energy.The ultimate load obtained has a higher consistency with the theoretical value.(2)According to the variation of strain in the loading process,the author proposed the criteria of the ultimate bearing capacity of components based on the strain mutation.In this paper,the law of the first principal strain of the concrete at the cross-section key point is analyzed.It is found that the first principal strain is abruptly increased and increases sharply.And the corresponding load value is the ultimate load,which is in good agreement with the calculated value.(3)Experimental verification of the ultimate bearing capacity obtained by the above two criteria was carried out.It was found that the ultimate bearing capacity obtained from the criterions were close to the experimental value,which verified the validity and applicability of the criteria proposed in the paper based on the elastic strainenergy and strain mutation,and provides reference for the study of the ultimate bearing capacity of other types of components or systems.