This document presents a nonlinear finite element analysis of a reinforced concrete slab tested by McNeice in 1967. A quarter-symmetric model of the slab was created in MSC/Marc using solid elements for the concrete and truss elements for the rebar. The concrete was modeled using damage plasticity to account for cracking and crushing. Load-deflection curves from the Marc analysis are compared to experimental test data and results from Abaqus. The analysis shows the slab initially cracking around 660 lbs and progressively cracking further until reaching ultimate load at 3,498 lbs. Crack patterns produced by Marc at different load levels are also presented.

1. Applied Analysis & Technology © 2015
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Analysis of Reinforced Concrete (RC) McNeice Slab Using Nonlinear Finite
Element Techniques MSC/Marc
Prepared By:
David R. Dearth, P.E.
Applied Analysis & Technology, Inc.
16731 Sea Witch Lane
Huntington Beach, CA 92649
Telephone (714) 846-4235
E-Mail AppliedAT@aol.com
Web Site www.AppliedAnalysisAndTech.com

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Introduction
 McNeice (1.) tested a reinforced concrete (RC) slab in 1967.
 The purpose of this summary is to present results of addressing this RC Slab and
computing the load deflection curve using MSC/Marc for comparison to the
experimental test data.
 For comparison purposes the results from Abaqus example problem 1.1.5 using
Abaqus/Explicate at tension stiffening case ε = 0.002 in/in are also compared.
 For rectangular plates (or slabs) no general expression for deflection of plates with
corner supports as a function of central concentrated loading is available. The loading to
produce (a.) initial cracking and (b.) ultimate capacity is computed using the Marc
Vector plots of element cracking strain.
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McNeice Slab Geometry with Rebar Definition
from Reference 1 No Scale
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Figure 1.1.5-1 McNeice Slab steel reinforcement locations (not to scale)
(Abaqus Examples Manual 1.1.5 Collapse of Concrete Slab)
3” o.c.

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Quarter Symmetric RC Slab with Boundary Conditions & Loading
X-Z Symmetric
Plane, BC = Ty
Symmetric Loading,
Ptot/4 for Qtr Sym
Idealization
Corner Vertical
Reaction, BC=Tz
Y-Z Symmetric
Plane, BC = Tx
Mesh size for the quarter
symmetric model is 12x12x4

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Quarter Symmetric RC Slab Rebar Idealization
3/16” dia.
Interior Rebar
Area = 0.0276 in2
3/16” dia. Rebar at
Plane of Symmetry
Area/2 = 0.0138 in2
3/16” dia. Rebar at
Plane of Symmetry
Area/2 = 0.0138 in2
Rebar Material Properties; Mild Steel
Es= 29x 106 psi ν =0.3
Yield Stress Fty = 60,000 psi
Bi-Linear-Plastic Modulus = Perfectly Plastic
X-Z Symmetric
Plane, BC = Ty
Y-Z Symmetric
Plane, BC = Tx
Rebar Spacing
3” o.c. Typ
Rebar Size 3/16” Dia.
Table 4.1 Slab No. 1 (1.)

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Concrete : Isotropic Tension Properties
The concrete is idealized using 3D solid elements. Young’s modulus of elasticity for the concrete is given as:
Concrete Material Properties
Es= 4.150 x 106 psi ν =0.15
Critical Cracking Stress (Rupture Stress) fr = 460 psi(2.)
Tension Softening Strain at Failure, ε = 0.002 in/in(2.)
Note: Abaqus input is “strain at failure”.
Marc input is “tension softening slope”.

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Concrete : Isotropic Compression Properties
The concrete is idealized using 3D solid elements. Young’s modulus of elasticity for the concrete is given as:
Concrete Material Properties
Es= 4.150 x 106 psi ν =0.15
Compressive Failure Stress f’
c = 5,550 psi(2.)
Crushing Strain, εc = 0.003 in/in (assumed)
Note: Plasticity definition data for MSC/Marc is defined as post-yield, or plastic, portion of the stress strain curve; e.g. yield
stress  zero net plasticity. Typical engineering data for stress-strain curves are defined as total nominal strain.
The compressive uniaxial stress-
strain relationship for the concrete
model was obtained using the multi-
linear isotropic stress-strain
equations for concrete from
MacGregor 1992(3.).

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Concrete : Isotropic Properties
The concrete is idealized using 3D solid elements. Young’s modulus of elasticity for the concrete is given as:
Concrete Material Properties
Elastic : Ee= 4.15 x106 psi ν = 0.15
Cracking : Critical Cracking Stress (Rupture Stress) fr = 460 psi
Softening Modulus, Es= 243,495 psi [Failure Strain = 0.002 in/in]
Crushing Strain, εc = 0.003 in/in, Shear Retention : 20%
Plasticity : Elastic-Plastic, Isotropic Hardening, Buyukozturk Concrete
Concrete Isotropic Material Input Dialog

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Rev “x”McNeice Slab Test Deflections vs MSC/Marc & Abaqus/Explicit

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Rev “x”Marc Concrete Crack Progression for McNeice Slab
660 lbs. Last Load Step Prior to Cracks
Crack Progression vs. Slab Loading
832 lbs. Cracks Begin to Appear
At Slab Center and Corner Support
1,286 lbs. Crack Propagation
At Slab Center and Corner Support
1,532 lbs. Crack Propagation
At Slab Center Out to Edges and
Corner Support
1,940 lbs. Crack Propagation
At Slab Center Out to Edges and
Corner Support
3,498 lbs. Crack Propagation
At Ultimate Load Prior to Full
Collapse

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References
1) McNeice, G.M., Elastic-Plastic Bending of Plates and Slabs by Finite Element
Method; Thesis Submitted to University of London for Degree Doctor of Philosophy,
Department of Civil and Municipal Engineering University College of London,
November 1967
2) Dassault Systems, 1.1.5 Collapse of Concrete Slab, Abaqus 6.11 Example Problems
Manual, Volume 1: Static and Dynamic Analyses, 2011
3) MacGregor, J.G. (1992), Reinforced Concrete Mechanics and Design, Prentice-Hall,
Inc., Englewood Cliffs, NJ.
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