Seyedali (Ali) Abolmaali, Ph.D.http://hdl.handle.net/10106/242532024-03-29T00:06:23Z2024-03-29T00:06:23ZComputational benchmarks in simulation of cyclic performance of steel connections using three dimensional nonlinear finite element methodAbolmaali, AliRazavi, MohammadKiamanesh, Roozbehhttp://hdl.handle.net/10106/244992023-12-12T15:49:22Z2012-01-01T00:00:00ZComputational benchmarks in simulation of cyclic performance of steel connections using three dimensional nonlinear finite element method
Abolmaali, Ali; Razavi, Mohammad; Kiamanesh, Roozbeh
The presented manuscript is intended to introduce accurate computational benchmarks to predict the hysteresis behavior of beam-column steel connections by means of a 3D non-linear finite element analysis. In this study, element type, inelastic material behavior, bolts pre-tensioning, and contact properties between different components of connections are discussed. Incremental nonlinear analysis takes into account all three types of nonlinearities including material, geometry, and contact properties in predicting moment-rotation hysteresis loops. A series of full-scale structural tests are performed to validate the results obtained from the finite element analyses. This study shows that cost efficient numerical analysis simulation is capable of replacing full-scale tests for steel connections.
2012-01-01T00:00:00ZA weighted residual parabolic acceleration time integration method for problems in structural dynamicsAbolmaali, AliRazavi, S.H.Ghassemieh, M.http://hdl.handle.net/10106/243262016-01-20T00:50:59Z2007-01-01T00:00:00ZA weighted residual parabolic acceleration time integration method for problems in structural dynamics
Abolmaali, Ali; Razavi, S.H.; Ghassemieh, M.
In the proposed method, the variation of displacement in each time step
is assumed to be a fourth order polynomial in time and its five unknown coefficients are
calculated based on: two initial conditions from the previous time step; satisfying the
equation of motion at both ends of the time step; and the zero weighted residual within
the time step. This method is non-dissipative and its dispersion is considerably less
than in other popular methods. The stability of the method shows that the critical time
step is more than twice of that for the linear acceleration method and its convergence
is of fourth order.
2007-01-01T00:00:00ZInvestigations of shear behavior in reinforced concrete boxesAbolmaali, Alihttp://hdl.handle.net/10106/243252023-12-07T17:26:38Z2008-01-01T00:00:00ZInvestigations of shear behavior in reinforced concrete boxes
Abolmaali, Ali
Box culverts have been used increasingly since 1965 to meet drainage requirements where the site conditions and loads acting upon them have been appropriate. It is believed that 80% of single barrel culvert installations are precast, and manufactured in a range of span and rise combinations. Box sections are typically defined by their span, rise, and design height of fill measured from finished grade to the top of the box section. The joint or “laying” length is a function of the form equipment accessible to the individual producer. The inside corners of the wall and slabs are tapered to create a haunch, which usually has equal horizontal and vertical dimensions. The haunch dimensions are equal to the wall thickness though some producers utilize form equipment, which yields a fixed haunch dimension. With the exception of the special design cases, the thickness of culvert walls, top slab and bottom slab varies from 4 inches to 12 inches (10 cm to 30 cm) and is a function of the span. Boxes are reinforced with the inside and the outside layers of plain or deformed steel welded wire reinforcement per ASTM A 185 (2001) and A 497 (2001). These reinforcing layers are proportioned to resist the calculated moments and thrusts in the member’s sections. Precast box sections used to be designed as per ASTM C 789 for highway loading with earth cover of 2 feet (61 cm) or more or as per ASTM C 850 for highway loading with earth cover less than 2 feet (61 cm). Since 2003, ASTM C 1433 (2003) has replaced C 789 and C 850 for both loading conditions. Precast box sections are typically cast by either the drycast or wetcast method with batches designed to yield 5000 psi (34.5 MPa). Drycasting is characterized by the use of very low water/cement (w/c) ratios (0.35 or less) while wetcast uses standard mix designs yielding slumps in the range of 4 inches (10 cm) to 6 inches (15 cm).
This article is an abstract of the study entitled, “Experimental and
Finite Element Based Investigations of Shear Behavior in Reinforced
Concrete Box Culverts
2008-01-01T00:00:00Z