Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Cyclic

Experimental Study and Numerical Simulation of Plane Steel Frame with Rubberized Connecting Technology Subjected to Seismic Effect

Suhaib J. Ali; Amer M. Ibrahim; Sarmad Shafeeq

Engineering and Technology Journal, 2021, Volume 39, Issue 3A, Pages 415-425
DOI: 10.30684/etj.v39i3A.1500

This paper represents experimental and numerical study the behavior of the rubberized steel frame connections. One single-bay, one-story without elastic buckling are cyclically tested. The experimental specimens are simulated and analyzed by the ABAQUS program. Four specimens of steel plane portal frame are investigated under horizontal reversed cyclic loads. The specimen connections are developed by using different diameters of composite steel bolts/rubber instead of conventional steel bolts to connect the beams with columns. The yield and ultimate strength, ductility, envelope curves, and damping ratio of these specimens are analyzed and compared. The finite element method is used to establish and verify the results of the laboratory test. The results of the experimental and numerical tests gave a large load-carrying capacity, reduction in the stresses, excellent ductility and energy dissipation capacity, and remarkably improved damping ratio.

Modelling The Behaviour Of Sand Under Strain-Controlled Loading BY The Finite Element Method

Omar al-Farouk S. al-Damluji; Mohammed Yousif Fattah

Engineering and Technology Journal, 2008, Volume 26, Issue 2, Pages 202-227

Strain-controlled tests are conventional in soil mechanics laboratories. It is
intended in this paper to simulate both triaxial and simple shear tests
theoretically by using the finite element method. The solution of the nonlinear
equations is obtained by several iterations. The Newton-Raphson with
tangent stiffness method in which the stiffness matrices are tangents is
adopted. The model used in this paper is the ALTERNAT model which
forms the major component of a double hardening model for the mechanical
behaviour of sand under alternating loading.
The finite element method is used in simulating the behaviour of round
uniform quartz sand under monotonic drained loading with constant mean
stress and cyclic constant volume loading (undrained). The monotonic test
was conducted with constant mean stress, where the specimen was
compressed in one direction and extended in other directions while the mean
stress (the average of the principal stresses) is kept constant and equal to 137
kPa. It is noticed that the peak stress is occurring at very small strain
(0.122). The stress-strain behaviour may be attributed to the particle
roundness and grain size uniformity.
In the cyclic tests, the specimen is sheared by cycling the shear strain while
the volume was kept constant. By doing this, an undrained strain-controlled
cyclic test similar to that typically done in many laboratories is numerically
It was found that the mean stress during shearing is higher than the initial
consolidation pressure. This implies that only negative pore pressures occur
in the first two cycles. A careful study shows that there exists an effective
stress ratio line or zero-dilatancy line in both compression and extension
regions, beyond which the specimen dilates.