MODELLING THE RESPONSE OF ISOLATED SLAB SPECIMENS USING EXPLICIT QUASI-STATIC FINITE ELEMENT ANALYSIS

Purpose: This paper assesses the analytic modelling of response of reinforced concrete isolated slab specimens using an explicit quasi-static nonlinear solution rather than the conventional implicit static nonlinear solution. The advantage of the former being its applicability to dynamic problems such as those associated with abnormal loadings on structures. Design/methodology/approach: Two isolated slab specimens (IA30d-32 and IA30a-25) which have been experimentally tested to fail in flexure and punching shear respectively were adopted for validation of the analytic model. Findings: Load displacement responses for both implicit static and explicit quasi-static solutions were found to be similar at a loading rate of about 10.575KNs-1. Kinetic energy of the system remained zero throughout the duration of the explicit quasi-static simulation with "mean strain rates" ranging between 10-8 s-1 to 10-6 s-1. Hence, the explicit quasi-static solution met the quasi-static loading range specified in Model Code 2010. Results of the analytic assessment were conservative, with 6.4% and 4.1% differences in flexural and punching shear strength respectively and 14% difference in rotation at punching shear failure. Research limitations/Implications: Assessment was limited to the flexural and punching shear response of isolated flat slab specimens. Originality/value: It was concluded that at low loading rates, explicit quasi-static analysis could be used in combination with the static failure criterion for the determination of the global response of flat slab structures.