By,
Amit H. Varma
1
University
Copyright, Amit H. Varma, Purdue Univ.
Design of Steel-Plate Composite (SC)
Walls
11/15/13
AISC N690: APPENDIX N9
OUTLINE
for Steel-Plate Composite Structures
Copyright, Amit H. Varma, Purdue Univ.
 Layout
11/15/13
 Specification
and Organization of N690 Appendix N9
 Presentation
 Ongoing
Modules and Links
Work
2
OBJECTIVE

Specification for steel-plate composite SC walls in
safety-related nuclear facilities
Copyright, Amit H. Varma, Purdue Univ.

11/15/13

Use with AISC N690 – LRFD code
Instead of ACI 349 code for concrete structures for
nuclear facilities  but all topics covered
 Specification
for SC walls and associated
connections
3
PATH FORWARD
 Develop
industry consensus standard for modular
composite construction
 NRC
review standard and publish regulatory guide
 AISC
N690-12: Specification for design of steel
structures for safety-related nuclear facilities
TC12 – established ad-hoc sub-committee
for modular composite construction
 AISC

First Meeting Nov. 2006
PATH FORWARD
 Sub-committee
for modular composite construction
 Has
20 active members
 First
Meeting Nov. 2006
 Conducted
a total of 164 meetings and numerous
conference calls
 Attendees
include guests from a variety of institutions
as well as international participation
SCHEDULE
 Schedule
for completion
 Ballot
1 – Nov. 2013
 Ballot
2 – June 2014 with public review comments
 Ballot
3 – Nov. 2014 with public review comments
4 – Jan. 2015 with final public review
comments
 Ballot
 ANSI
approved standard
SCHEDULE
 US
NRC has started the review process using the
public review ballot no. 2
 Regulatory
Guide based on N690-12 has been
initiated, number allocated.
 NRC
position on the ANSI approved standard
should come shortly after.
LAYOUT AND ORGANIZATION OF APP N9
Specification Additions
– Materials
 NB2
– Loads and Load Combinations
Add F and H, and tread them like D and L (ACI 349)
 NM2

Copyright, Amit H. Varma, Purdue Univ.
 NA3

11/15/13
 N690-12
– Fabrication, Erection, and Construction
Dimensional Tolerances
 Minimum
Requirements for Inspection of Composite
Constructions
8
LAYOUT AND ORGANIZATION OF APP N9
Design Requirements
General Provisions
 N9.1.2
Design Basis

N9.1.2a Required Strength

N9.1.2b Design for Stability
 N9.1.3
Compactness Requirement
 N9.1.4
Requirements for Composite Action

N9.1.4a Classification of Shear Connectors

N9.1.4b Spacing of Shear Connectors
 N9.1.5
Copyright, Amit H. Varma, Purdue Univ.
 N9.1.1
11/15/13
 N9.1
Tie Requirements

N9.1.5a Classification of Ties

N9.1.5b Required Tension Strength for Ties
9
LAYOUT AND ORGANIZATION OF APP N9
Design Requirements (cont’)
 N9.1.6
Design for Impulsive and Impactive Loads
N9.1.6a Definition of Loads

N9.1.6b Dynamic Increase Factors

N9.1.6c Ductility Ratios

N9.1.6d Response Determination
 N9.1.7
Design and Detailing Around Opening

N9.1.7a Design and Detailing Requirements Around
Small Openings

N9.1.7b Design and Detailing Requirements Around
Large Openings
Copyright, Amit H. Varma, Purdue Univ.

11/15/13
 N9.1
10
LAYOUT AND ORGANIZATION OF APP N9
Analysis Requirements
General Provisions
 N9.2.2
Effective Stiffness for Analysis
 N9.2.3
Geometric and Material Properties for Finite
Element Analysis
 N9.2.4 Analyses
Involving Accidental Thermal
Conditions
 N9.2.5
Determination of Required Strengths
Copyright, Amit H. Varma, Purdue Univ.
 N9.2.1
11/15/13
 N9.2
11
LAYOUT AND ORGANIZATION OF APP N9
Design of SC Walls
Uniaxial Tensile Strength
 N9.3.2
Compressive Strength
 N9.3.3
Out-of-Plane Flexural Strength
 N9.3.4
In-Plane Shear Strength
 N9.3.5
Out-of-Plane Shear Strength
 N9.3.6
Strength Under Combined Forces

N9.3.6a Out-of-Plane Shear Forces

N9.3.6b In-Plane Membrane Forces and Out-of-Plane
Moments
Copyright, Amit H. Varma, Purdue Univ.
 N9.3.1
11/15/13
 N9.3
12
LAYOUT AND ORGANIZATION OF APP N9
Design of SC Wall Connections
General Provisions
 N9.4.2
Required Strength
 N9.4.3 Available
Strength
Copyright, Amit H. Varma, Purdue Univ.
 N9.4.1
11/15/13
 N9.4
13
FLOWCHART: DESIGN AND SPECS
11/15/13
Begin design of structure with SC walls
2. Check that applicable requirements of Section N9.1.1 are satisfied.
Are the
requirements of
N9.1.1 satisfied?
Yes
Continue
No
Copyright, Amit H. Varma, Purdue Univ.
1. Check that SC section thickness, reinforcement ratio, faceplate thickness, steel and
concrete grades satisfy the limitations of Section N9.1.1.
Appendix N9 is not applicable.
(Refer to Commentary for
alternate methods)
14
FLOWCHART: DESIGN AND SPECS
Continue
11/15/13
Check that faceplate is compact (Section N9.1.3)
Provide structural integrity using ties
Check tie spacing using Section N9.1.5.
Check tie spacing in regions around openings using Section N9.1.7.
Classify ties as yielding or nonyielding using Section N9.1.5a.
Ties contribute to out-of-plane shear strength of SC walls according to Section N9.3.5
Calculate minimum required tension strength for ties using Section N9.1.5b.
Copyright, Amit H. Varma, Purdue Univ.
Provide composite action using shear connectors
Classify connectors as yielding or nonyielding type using Section N9.1.4a.
Check spacing of shear connectors using Section N9.1.4b
15
Continue
FLOWCHART: DESIGN AND SPECS
Continue
11/15/13
Develop linear elastic finite element (LEFE) model according to Sections N9.2.1 and N9.2.3
Perform LEFE analysis to calculate design demands and required strengths.
Identify interior and connection regions using Section N9.1.2
Calculate required strengths for each demand type using SectionN9.2.5
Copyright, Amit H. Varma, Purdue Univ.
Analyze LEFE model for load and load combinations from Section NB2.
Model openings using Section N9.1.7.
Model flexural and shear stiffness of SC walls using Section N9.2.2.
Loading due to accidental thermal conditions will be as per Section N9.2.4.
Model second-order effects using Section N9.1.2b
16
Continue
FLOWCHART: DESIGN AND SPECS
Continue
11/15/13
Calculate available strengths for each demand type using Section N9.3.
The sub-sections are:
Available uniaxial tensile strength using Section N9.3.1
Available compressive strength using Section N9.3.2
Available out-of-plane flexural strength using Section N9.3.3
Available in-plane shear strength using Section N9.3.4
Available out-of-plane shear strength using Section N9.3.5
Check available strength for combined forces using Section N9.3.6
Combined out-of-plane shear demands using Section N9.3.6a
Combined in-plane membrane forces and out-of-plane moments using Section
N9.3.6b
Copyright, Amit H. Varma, Purdue Univ.
Design Process for SC Walls: Required strengths ≤ Available strengths
17
Continue
FLOWCHART: DESIGN AND SPECS
Continue
11/15/13
Select full strength or overstrength connection design philosophy, and
design force transfer mechanisms for connections as per Section N9.4.1.
Calculate connection required strength for each demand type
in accordance with Section N9.4.2
Calculate connection available strength using Section N9.4.3
Check connection required strength ≤ connection available strength
Check SC wall design for impactive and impulsive loads
in accordance with Section N9.1.6
Copyright, Amit H. Varma, Purdue Univ.
Design Process for SC Wall Connections
18
Continue
FLOWCHART: DESIGN AND SPECS
Continue
2. Specify dimensional tolerances for fabrication of SC wall panels, sub-modules, and
modules using Section N9.5
Specify quality assurance/quality control requirements for SC walls in
accordance with Section N9.6
End design of structure
with SC walls
Copyright, Amit H. Varma, Purdue Univ.
1. Specify detailing for regions around openings using Section N9.1.7
11/15/13
Fabrication, Erection and Construction Requirements
19
PRESENTATION MODULES
11/15/13
Module 2:
Analysis
Requirements and
Recommendations
Module 3:
Shear Connectors,
Local buckling
Composite Action
Copyright, Amit H. Varma, Purdue Univ.
Module 1:
General Provisions,
Requirements,
Limitations
20
PRESENTATION MODULES (CONTD.)
11/15/13
Copyright, Amit H. Varma, Purdue Univ.
Module 4:
Tie Bars
Design requirements
Out-of-Plane Shear
Module 6:
Design Interaction
equations for
combined forces
and moments
Module 5:
Available Strength
Tension, Compression
Flexure, In-Plane
Shear
Module 7:
Connection
Design
21
PUBLIC ACCESS TO PRESENTATION MODULES
http://meetings.nrc.gov/pmns/mtg?do=details&Code=20132
234
 Meeting
summary:
http://pbadupws.nrc.gov/docs/ML1334/ML13340A018.pdf
 All
slides and discussion notes from meeting below:
http://pbadupws.nrc.gov/docs/ML1335/ML13350A009.pdf
Copyright, Amit H. Varma, Purdue Univ.
A.H.* (2014). “Draft Provisions on Modular
Composite Construction Under Consideration by AISC
N690, Appendix N9.” Presentation to the Nuclear
Regulatory Commission (NRC), Public Meeting.
 Meeting announcement:
11/15/13
 Varma,
22
DEVELOPMENT OF AN AISC DG
 First
initiated: May 2014
major submission for review: Oct. 2014
 Second
 Third
major submission for review: Jan. 2015
major submission for review: July 2015
Copyright, Amit H. Varma, Purdue Univ.
 Work
Guide on SC Composite Walls
11/15/13
 Design
23
 Finalization
of DG: Nov. 2015
PAST AND CURRENT WORK
 Testing
of modular composite wall design for
current nuclear plant designs
 Full-scale
tests to confirm design equations and
performance
 Scaled
tests to confirm strength and ductility for
earthquake loading
 Full-scale
tests for combined accident thermal and
seismic loading
 Confirmatory
tests of connection behavior
PAST AND CURRENT WORK

Numerical simulation of modular composite structure
response to seismic events, accident thermal + seismic
event (Fukushima type scenario),
 Numerical
simulation of modular structure response
to aircraft impact
 Experimental
confirmation and numerical simulation
of connection behavior, performance and failure
modes
CURRENT WORK
 Development
of connection strategies and
technologies for modular composite construction
by the DOE – NEET, Advanced Methods
of Manufacturing program
 Experimental testing
 Numerical simulation
 Development of design guidelines for:
 Sponsored
SC wall-to-concrete basemat anchorage
 SC wall-to-wall T and L connection
 SC wall-to-slab connection

CURRENT WORK
 Modular
composite structures subjected to accident
thermal conditions and seismic loading
by DOE – NEUP Program, Advanced
Methods of Manufacturing
 Experimental testing
 Numerical simulation
 Development of design and analysis guidelines
 Sponsored

Effects of accident thermal loading on in-plane shear
behavior of SC and RC walls
CURRENT WORK
 Design
of modular composite structures for
impulsive and impactive loading
 Sponsored
by the US NRC and DOE
 Experimental testing in US ACoE facility
 Numerical simulations
 Development of design guidelines
Impulsive loading tests – conducted Oct. 2014
 Missile Impact tests – 2015, 2016

FUTURE WORK
 Use
of stainless steel and other corrosion resistant
systems in modular composite construction for
SMRs
 Use
of curved walls in modular composite
construction, particularly use of combined
containment vessel and shield building
 Effects
of structure-soil-structure interaction in the
design of modular composite structures
PUTTING THE ‘M’ IN SMRS
 Construction
 Various
 Project
schedule & success
innovative and efficient designs
specific testing and analysis minimized
 Development
of ANSI approved AISC Specification
and NRC regulatory guide
 Outline
of AISC N690-12 Supp. No. 1
PUTTING THE ‘M’ IN SMRS
 Numerous
testing, simulation, and design projects
conducted at Purdue for current power plant designs
using modular composite structures.
 Current
Research Projects, funded by US DOE and
US NRC, at Purdue to facilitate modular composite
structures for SMRs
 Challenges
 Making
overcome
modularity in construction a reality …