Analysis On Plastic Effect Of Non-linear Metal Frame Structure

The design of high-strength steel and stainless steel frame structure relies heavily on the design of steel structures EN 1993-1-1: 2005(Eurocode)or steel structure design specification GB50017-2003(Chinee code).There are limited studies on the accuracy of design guidelines for aluminium alloy frame structures due to the limited empirical studies.To the best of my knowledge,this is the first study to directly compare the plastic effect of aluminium,stainless steel,and high-strength steel frame structures.The metal frame structure considers in this study was modeled using 6061-T4 aluminium,S316 stainless steel,and Q550 high-strength steel.6061-T4 aluminium was selected for this study because of its high strength ratio,good corrosion resistance,machinability,and weldability.S316 stainless was selected over other classes of stainless steel because of their improved properties such as corrosion,etc.Q550 high-strength steel was selected for this study due to its improved mechanical properties and atmospheric corrosion resistance.To respond to the research problem,the following tasks were performed(1)Review previous study to examine which of the aluminium,stainless steel grade,and high-strength grade has the required mechanical properties that are suitable for the study;(2)Reviewed both Eurocode code(such as Basis of structural analysis design EN1990-1-1:2005;design of steel structures: general rules and rules for buildings EN1993-1-1: 2005;design of steel structures: stainless steels EN 1993-1-4: 2006;design of aluminium structures: general structural rules EN 1999-1-1:2007;and design of aluminium structures: general structural rules EN 1999-1-1:2007)and Chinese code(such as steel structure design specification GB50017-2003;specification for aluminium alloy structural design: GB50429-2007;and Technical specifications for stainless steel structures CECS410-2015)to understand the design procedure suggested in these design code;(3)An experiment by Wakabayashi et al.,1967 was used to validate the design method used in this study.The experiment was one-quarter scale single-layer single-span and two-layer single-span Q235 steel frame structure.Findings from a finite element analysis based on the design method used in this study were compared to results from the experiment.The difference in results was ±5 percentage which is within the acceptable range;(4)After verifying the design method,the study analyzed the plastic effect of a metal frame structure modeled as a single-layer single-span,two-layer single-span,and two-layer two-span frame structure.The model was chosen primarily because preliminary analysis of the plastic effect of 6061-T4 aluminium high-rise buildings frame structure indicated that the plastic effect is small in high-rise buildings and therefore should be neglected;(5)Direct analysis of the material frame structure was performed using ABAQUS and compared with the second-order elastic analysis;(6)To obtained the plastic effect,external loads were applied to the metal frame structure.The loads were adjusted to obtain a plastic effect co-efficient from 0.6 to 1.20.The plastic effect of each plastic effect co-efficient was obtained.According to the findings of the study,the plastic effect of Q550 high-strength steel frame structures when the plastic effect co-efficient is <0.9 is zero and therefore can be ignored.6061-T4 Aluminium frame structures had the highest plastic effect.Additionally,Q550 high-strength frame structures had the lowest plastic effect among all the metal frame structures.Finally,among all the metal frame structures Q550 high-strength steel frame structures had the most significant percentage increase in plastic effect when the plastic co-efficient was increased from 0.98 to 1.20.;and(7)Member checks for a single-layer single-span Q460 high-strength steel frame structure for both Eurocode and Chinese code using the same model,loading conditions,and sectional properties were performed.According to the finding of the analysis,the column slenderness ratio met the design requirement for European code whilst it didn’t satisfy the design requirement for the relevant Chinese code.Also,the effective properties of the beam’s web under the Chinese code did not meet the requirement of the code.