by Click the blue character to focus on our authors Li Guochang, Liu Lu and Yang Zhijian’s summary: the mechanical performance of concrete-filled square steel tubular members with built-in I-shaped CFRP profiles under lateral impact load is studied by using ABAQUS finite element analysis software.
The material strength is calculated by considering the strain rate effect of the material under the dynamic response, and the finite element model is established to study the whole impact process, the stress-strain relationship and the energy dissipation state of the component.
By changing the impact energy, steel content, shear span ratio and material strength, the impact resistance of members is analyzed.
The results show that the built-in CFRP I-section makes the members have better energy dissipation and deformation capacity; With the increase of impact energy and shear span ratio, the mid span deflection of members increases and the time required to resist impact increases; The peak value of impact force is little affected by concrete strength, but it increases significantly with the increase of impact energy, steel content and yield strength of steel pipe.
Key words: I-shaped CFRP profile; Concrete filled steel tube; Lateral impact; Strain rate effect; Abstract: the finite element software abaquswased by the lateral impact behavior of concrete filled square steel tubular beam with I-shaped CFRP profiles Thestrengthofmaterialswascalculatedbyconsideringthestrainrateeffectofmaterialsunderdynamicload,andthefiniteelementmodelwasbuilttostudythewholeprocessofimpact,stress-strainrelationshipandenergystate.
Theinfluencesofimpactenergy,steelratio,shearspanratioandmaterialstrengthonthelateralimpactresistancebehaviorofmemberswerestudiedthroughparametricstudies.
Theresultsshowthattheconcrete-filledsquaresteeltubularbeamswithCFRPprofileshavebetterenergydissipationanddeformationcapacity.
Inaddition,withtheincreaseofimpactenergyandshearspanratio,themid-spandeformationofbeamsandthedurationtimeofimpactloadincreases.
Theconcretestrengthhaslittleeffectonthelateralimpact,butitincreasesobviouslywiththeincreaseofimpactenergy,steelratioandyieldstrengthofsteeltube.
Keywords:I-shapedCFRPprofile; concrete-filledsteeltube; lateralimpact; strainrateeffect; In recent years, concrete filled steel tubular (CFST) has been widely used in various structural facilities and engineering construction fields with the advantages of mechanical properties and construction properties.
Scholars have studied its mechanical properties in many aspects and achieved a large number of research results [1-2].
In addition, with the development of building structures and materials towards higher performance, FRP composites with the characteristics of light weight and high strength are widely used in civil engineering industry, and many new types of concrete-filled steel tubular structures combined with FRP composites also appear.
Based on a lot of research on concrete-filled steel tubular and FRP materials, a new FRP profile concrete-filled steel tubular composite structure is proposed [3].
At present, many studies have been carried out on the static performance of the new member, such as axial compression, bias and bending performance, and many research results have been obtained [4-6].
However, during the service period, in addition to bearing the static load, the building structure may also suffer from accidental loads such as ship and car impact, resulting in serious damage or even loss of bearing capacity, and loss of life and property.
Therefore, it is necessary to study the performance of structures and members under impact load.
Scholars at home and abroad have done a lot of research on the impact resistance of concrete-filled steel tubular members..
