Research Reports

RP20-9: Wei-Wen Yu Center for Cold-Formed Steel Structures (1990-2020)
This report chronicles the history and activities of the Wei-Wen Yu Center for Cold-Formed Steel Structures, which closed in 2020.

RP20-8: Investigation of Bolted Connections in Cold-Formed Steel Members Using SAE J429 Bolts
The research compared ASTM and J429 bolt standards in terms of tensile strength, chemical and mechanical properties, shanks length, head size, thread profile and bolt styles. 

RP20-7: Benefits of Including SAE Bolts, Nuts and Washers in the AISI STANDARD S100
The addition of SAE J429 bolts to AISI S100 would allow practitioners to use a broader range of fasteners for the design of cold-formed steel structures. 

RP20-6: Experimental and Numerical Comparison of Flexural Capacity and Light Gage Cold-Formed Steel Roof Deck
The report presents an analysis of experimental data and compares it to two numerical analysis methods of light gage cold-formed steel roof deck. 

RP20-5: Structural Design Example - Four Span Metal Building Z-Purlin Line Supporting a Standing Seam Roof
This project provides an example step-by-step calculation of the new approach provided in AISI S100-16, Section 16.1. 

RP20-4: Cold-Formed Steel Bracing Design Using Combinations of Discrete and Sheathing Bracing
The report summarizes efforts related to establishing the behavior and design of cold-formed steel wall assemblies potentially braced by discrete steel bracing and wall sheathing. 

RP20-3: The Challenge of Calculating U-Factors for Cold-Formed Steel C-Shape Wall Assemblies Using Framing Factors
The objective of this project was to determine whether the framing factor for cold-formed steel C-shape frame walls was an acceptable metric to account for the thermal impact on U-factors due to the additional studs, tracks, plates, headers and sills beyond those of clear walls.

RP20-2: Development of a U-Factor Calculation Procedure for Cold-Formed Steel C-Shaped Clear Wall Assemblies
The objective of this project was to develop a simplified calculation procedure for an ANSI standard that could easily be used by architects, engineers and building owners to evaluate building envelope designs which could demonstrate compliance with the energy codes such as ASHRAE Standard 90.1, the International Energy Conservation Code, as well as state and local adopted energy codes.

RP20-1: Inelastic Lateral-Torsional Buckling Strength Validation for Non-Principal Axis Bending Using Numerical Methods
The current design specification for point-symmetric cold-formed steel members in North America (AISI S100) applies a conservative simplification for elastic lateral-torsional buckling. This report aims to provide additional validation of a recently proposed design approach. 

RP19-3: Direct Strength Prediction of Purlins with Paired Torsion Bracing
A methodology to predict the local and distortional buckling strength of purlins with paired torsion bracing using the Direct Strength Method has been developed. 

RP19-2: Thermal Bridging in Cold-Formed Steel Wall Assemblies 
The objective of this research project was to quantify the magnitude of energy loss through cold-formed steel stud wall assemblies and to lay the groundwork for future works that promote sustainable, energy-efficient and improved building design recommendations. 

RP19-1: Strength of Steel-to-Steel Screw Connections—Update to Provisions
The objective of this project is to review the existing provisions of AISI S100-16, North American Specification for the Design of Cold-Formed Steel Structural Members2016 Edition, for screw connections loaded in shear and tension (but not combined actions).

RP18-4: Load Bearing Clip Angle Design — Phase II
This is the second phase of a research project aimed at developing design methods for three limit states of cold-formed steel clip angles: shear, compression and pullover of the screw connections. This report investigates the fastener pattern effects on the behavior and strength of clip angles, the serviceability of clip angles subjected to tension, and the strength and behavior of clip angles subjected to combined shear and bending. 

RP18-3: Determination of Effective Standoff in Standing Seam Roof Systems 
This test program was undertaken to better understand the horizontal force transfer between a purlin and standing seam sheathing. 

RP18-2: Design Example for Analytical Modeling of a Curtainwall and Considering the Effects of Bridging (All-Steel Design Approach)
The document illustrates how to apply the provisions in AISI S100-16, North American Specification for the Design of Cold-Formed Steel Structural Members, in a practical example by analytically modeling a curtainwall and considering the effects of bridging. The modeling procedure may also be applicable to other framing systems. 

RP18-1: Thermal Analysis of Cold-Formed Steel Wall Assemblies
The research for this report was conducted to support the development of a calculation methodology for determining the U-factors and R-values for wall assemblies containing cold-formed steel. 

RP17-6: Higher Capacity Cold-Formed Steel Sheathed and Framed Shear Walls for Mid-Rise Buildings: Part 2
The main objective of the research was to develop a design procedure for cold-formed steel sheathed and framed shear walls to achieve higher strength and ductility and to resist the larger forces expected in mid-rise construction. 

RP17-5: Higher Capacity Cold-Formed Steel Sheathed and Framed Shear Walls for Mid-Rise Buildings: Part 1
The main objective of the research was to develop a design procedure for cold-formed steel sheathed and framed shear walls to achieve higher capacity and ductility to resist the higher forces experienced in mid-rise construction. 

RP17-4: Higher Strength Cold-Formed Steel Framed/Steel Shear Walls for Mid-Rise Construction
The objectives of the research project were to: 1) analyze the influence of the wall length for shear walls designed and built with quarter point frame blocking members, and 2) determine the influence of the framing thickness on the performance of the shear walls.

RP17-3: AISI Standards Development Strategic Planning—Process, Responsibilities and Priorities
This paper provides a description of the strategic planning process and its significant outcomes, which will guide the efforts of AISI standards development over the next cycle and beyond. 

RP17-2: Monotonic and Cyclic Response of Single Shear Cold-Formed Steel-to-Steel and Sheathing-to-Steel Connections
This report derives monotonic and cyclic load-deformation backbone and pinching parameter models for cold-formed steel screw-fastened connections.

RP17-1: Experimental Study on System Reliability of Cold-Formed Steel Roof Trusses
This report presents a research project aimed at advancing the treatment of cold-formed steel structural reliability in roof trusses.

RP16-3: Direct Strength Prediction of Cold-Formed Steel Beam-Columns
This report covers a new formulation for the Direct Strength Method that can account for stability and strength under multiple actions.

RP16-2: Characterization of Cold-Formed Steel Framed Diaphragm Behavior
This research focused on the characterization of behavior under in-plane loading of CFS framed - wood sheathed diaphragms.

RP16-1: Resistance of Arc Spot Welds - Update to Provisions
This report updates the provisions of the AISI S100-12 standard for strength of arc spot welds loaded in shear and tension based on the results of four new research studies.

RP15-3: Advancing Seismic Simulation of Cold-Formed Steel Framed Buildings
An analysis framework for cold-formed steel structures that captures the nonlinear cyclic behavior of critical components is presented.

RP15-2: Load Bearing Clip Angle Design (Updated March 2016)
This project developed appropriate design methods for load-bearing cold-formed steel clip angles under three different loading conditions.

RP15-1: Direct Strength Method for Steel Deck
This project determines and compares the behavior and usable strength of existing floor and roof deck sections with both DSM and EWM.

RP13-3: Report on Laboratory Testing of Fastening of Cold-Formed Steel Track to Concrete Base Materials With Power-Actuated Fasteners
Research demonstrates that tested capacities of the CFS track-to-concrete PAF connections exceed those used for design under current ASCE 7 (2010) provisions.

RP13-2: Energy Dissipation of Thin-Walled Cold-Formed Steel Members
The report summarizes research that investigated the cyclic behavior and energy dissipation of cold-formed steel C-section structural axial and flexural framing members.

RP13-1: Sheathing Braced Design of Wall Studs
The report examines the axial behavior and axial + bending behavior of cold-formed steel stud walls braced solely by sheathing connected to the stud and track flanges.

RP10-5: LRFD and LSD Resistance Factors for Cold-Formed Steel Compression Members
This report covers the recalibration of LRFD and LSD resistance factors for cold-formed steel compression members when the strength is predicted using the Direct Strength Method.

RP10-4: Cold-Formed Steel Framing Seismic Design Optimization - Phase 1a - Seismic Equivalency Parameter Evaluation
This report includes an initial evaluation of seismic equivalency parameters for cold-formed steel framed shear walls with wood structural panel and steel sheet sheathing.

RP10-3: Report on Laboratory Testing of Anchor Bolts Connecting Cold-Formed Steel Track to Concrete With Minimum Edge Distances
This research project evaluates the behavior of the cold-formed steel track-to-concrete anchor bolt connection.

RP10-2: Cold-Formed Steel Bolted Connections Using Oversized and Slotted Holes Without Washers - Phase 2
This Phase 2 report gives an evaluation of the behavior and strength of bolted cold-formed steel connections with oversized and slotted holes without using washers.

RP10-1: Development of Canadian Seismic Design Provisions for Steel Sheathed Shear Walls
The objective of this research was to develop Canadian-specific design provisions for ordinary steel-sheathed shear walls.

RP09-3: Screw Connections Subject to Tension Pull-Out and Shear Forces
This study provides data that allows the formulation of a methodology to design screw connections subject to this limit state.

RP09-2: Steel Sheet Sheathing Options for Cold-Formed Steel Framed Shear Wall Assemblies Providing Shear Resistance - Phase 2
This Phase 2 project confirms the discrepancy in the published nominal strength of 27-mil sheets discovered by the Phase 1 project, and proposes new values.

RP09-1: Direct Strength Design of Cold-Formed Steel Members with Perforations
This research project extends the appealing generality of the Direct Strength Method to coldā€formed steel beams and columns with perforations.

RP08-11: Cold-Formed Steel Bolted Connections Without Washers on Oversized and Slotted Holes - Phase 1
This research aims to experimentally investigate three typical failure modes in cold-formed steel bolted connections with the non-washer and oversized configurations.

RP08-10: Section Properties for Cellular Decks Subjected to Negative Bending
The primary objective of this research was to modify the method developed by Luttrell and Balaji such that the dimensional reduction factor is non-dimensional.

RP08-9: Deep Deck and Cellular Deck Diaphragm Strength and Stiffness Evaluation
The goal of this research was to examine the performance of deep deck and cellular deck diaphragms.

RP08-8: An ATC-63 Study in Support of the Proposed System Performance Factors for AISI S110 Standard for Seismic Design of Cold-Formed Steel Structures: Special Bolted Moment Frames
The objective of this study was to verify the adequacy of the proposed Seismic Performance Factors for the newly developed AISI S110.

RP08-7: Estimation of Sound Transmission Class and Impact Insulation Class Rating for Steel-Framed Assemblies
This document provides additional sound transmission class (STC) and impact insulation class (IIC) ratings for a number of walls and floors.

RP08-6: Reinforcement Schemes for CFS Joists Having Web Openings
Presented in this report are the findings from an extensive testing program conducted at McMaster University on full-scale floor joists having larger web openings.

RP08-5: Inelastic Performance of Screw-Connected Cold-Formed Steel Strap Braced Walls
This report presents findings to verify the capacity-based design approach, the Rd and Ro values, and the building height limit as found in AISI S213-07.

RP08-4: Inelastic Performance of Welded Cold-Formed Steel Strap Braced Walls
The research provides verification of the capacity-based design approach, the Rd and Ro values and the building height limit as found in AISI S213 for limited ductility CBFs.

RP08-3: Flexural Behavior and Strength of Cold-Formed Steel L-Headers
Findings are presented from an extensive testing program of full-scale single and double cold-formed steel L-headers.

RP08-2: Analytical Study on Rotational Restraint of Sheathing
This report is a supplement to the July 2007 report on Experiments on Rotational Restraint of Sheathing by Schafer, Sangree and Guan.

RP08-1: Strength of Cold-Formed Steel Jamb Stud-To-Track Connections
Design expressions are proposed to predict the capacity of this connection for two limit states: web crippling of the jamb stud and punch-through of the track.

RP07-3: Steel Sheet Sheathing Options for Cold-Formed Steel Framed Shear Wall Assemblies Providing Shear Resistance
The findings from an extensive monotonic and cyclic testing program of 30-mil and 33-mil steel sheet sheathed shear walls with 2:1 and 4:1 aspect ratios are presented.

RP07-2: Experiments on Rotational Restraint of Sheathing
The objective of this project was to perform tests in accordance with AISI TS-1-02 to experimentally determine the rotational restraint that sheathing provides to joists.

RP07-1: Performance of Steel Products Coated with Zinc and Zinc Alloys in Pressure Treated Wood
This project was part of an investigation to establish reliable life prediction data for galvanized steel products used with currently available pressure-treated woods.

RP06-3: Comparison of AISI Specification Methods for Members With Single Intermediate Longitudinal Stiffeners
This study compares the B4.1 and B5.1 methods for calculating the effective widths of longitudinally stiffened elements.

RP06-2: Residential Hip Roof Framing Using Cold-Formed Steel Members
This project investigated a more rational rafter design methodology for both gable and hip roofs.

RP05-6: Strength of Cold-Formed Steel Floor Assemblies with Clip Angle Bearing Stiffeners
The results of 120 end-two-flange loading tests of typical floor configurations carried out to check and compare joist depth and thickness are presented.

RP05-5: Key Seismic Design Parameters: Steel and Wood Light-Frame Shear Wall
The objective of this project was to compare the requirements for use of the overstrength factor.

RP05-4: Experimental Evaluation of the Strength and Behaviour of 16- and 18-Gauge Cold-Formed Steel Top Track Systems
The objective of this project was experimental determination of the strength and stiffness of load-bearing top track assemblies.

RP05-3: Cold-Formed Steel Walls with Fiberboard Sheathing – Shear Wall Testing
The results of these tests are available to serve as the basis of a code change to permit use of fiberboard sheathing on steel-framed walls.

RP05-2: Cold-Formed Steel Gable End Wall Design Using the Prescriptive Method for One and Two Family Dwellings
This report presents the tables and details necessary to incorporate gable end wall design into future editions of the Prescriptive Method.

RP05-1: Distortional Buckling of Cold-Formed Steel Members in Bending
This report includes the results of two series of bending tests on industry standard cold-formed steel C- and Z-sections.

RP04-4: Corrosion of Galvanized Fasteners Used in Cold-Formed Steel Framing
This research program investigated the potential for corrosion of galvanized fasteners used in cold-formed steel framing.

RP04-3: Summary Report: Strength of Single L-Headers
This report summarizes a previous test program conducted at the NAHB Research Center, and proposes a design methodology for single L-headers under gravity load.

RP04-2: Strength of Screw Connections Subject to Shear Force
This report summarizes a study related to the design of cold-formed steel screw connections.

RP04-1: Bracing Requirements of Cold-Formed Steel Cee-Studs Subjected to Axial Compression
This research program was conducted to experimentally determine rational requirements for nodal bracing strength and stiffness demand of lipped cee-studs.

RP03-7: Estimating the Response of Cold-Formed Steel Frame Shear Walls
This project developed a method to estimate the drift deflection of cold-formed steel frame shear walls.

RP03-6: The Strength of Stiffened Cold-Formed Steel Floor Joist Assemblies with Offset Loading
This report describes the results of an experimental investigation into the response of cold-formed steel floor assemblies to variations in the alignment of the components.

RP03-5: Cold-Formed Steel Top Load Bearing Tracks
This report investigates the feasibility of using three different configurations of steel top load-bearing track assemblies.

RP03-4: Hybrid Wood and Steel Sole Plate Connection Walls to Floors Testing Report
This report is a summary of the testing procedures and results used to develop the hybrid wall-to-floor connection detail.

RP03-3: Testing of Steel Single L-Headers
This report investigates the structural adequacy of single steel L-headers for short openings in steel-framed residential buildings.

RP03-2: Cold-Formed Steel Frame and Beam-Column Design
The objective of this research was to make improvements in the Rack Manufacturers Institute (1997) Specification and the AISI (1996) Specification.

RP03-1: Web Crippling of Cold-Formed Steel Multi-Web Deck Sections Subjected to End One-Flange Loading
This study investigated the web crippling capacity of partially-fastened deck sections and re-entrant deck sections under the same loading conditions.

RP02-9: Development of Cost-Effective, Energy-Efficient Steel Framing: Thermal Performance of Slit-Web Steel Wall Studs
This report presents the results of thermal studies that were performed at the NAHB Research Center on prototype slit web studs.

RP02-8: Development of Cost-Effective, Energy Efficient Steel Framing: Structural Performance of Slit-Web Steel Wall Studs
This report presents the results of structural tests that were performed at the NAHB Research Center on a prototype slit web stud.

RP02-7: Performance of Cold-Formed Steel-Framed Shear Walls: Alternative Configurations
The findings presented in this report provided a basis for establishing design options for shear walls in the AISI Standard for Cold-Formed Steel Framing – Lateral Design.

RP02-6: Standard Test Method for Determining the Web Crippling Strength of Cold-Formed Steel Members
The object of this work was to develop a standard test method that could be used to establish the web crippling strength of cold-formed steel members.

RP02-5: Test Verification of the Effect of Stress Gradient on Webs of Cee and Zee Sections
The project evolved in response to the inconclusive nature of existing test data on Cees and Zees in bending.

RP02-4: Self-Drilling Screw Connections Subject to Combined Shear and Tension
The objective of this study was to develop a design equation that will represent the behavior of a self-drilling screw connection when it is exposed to combined shear and tension.

RP02-3: Overhang Effects on End-One-Flange Web Crippling Capacity of Cold-Formed Steel Members
The primary focus of this investigation involved the study of web-crippling behavior in single web cold-formed steel structural members.

RP02-2: Web Crippling and Bending Interaction of Cold-Formed Steel Members
Based on the results of this investigation, new web crippling and bending interaction equations have been developed.

RP01-8: Axial Strength of Purlins Attached to Standing Seam Roof Panels
The purpose of this research was to determine the axial load capacity of Z-purlins with one flange attached to a standing seam roof system.

RP01-6: Arc Spot Welds in Sheet-to-Sheet Connections
An analytical assessment of the current literature pertaining to sheet-to-sheet arc spot weld connections results in a proposed design recommendation.

RP01-5: Calibrations of Bolted Cold-Formed Steel Connections in Bearing (With and Without Washers)
This report contains the calibration results of single and double shear cold-formed steel-bolted connections that failed in bearing.

RP01-4: Testing of Bolted Cold-Formed Steel Connections in Bearing (With and Without Washers)
Contained in this report are the test results of double and single shear cold-formed steel bolted connections failing in bearing.

RP01-3: Experimental Determination of Required Lateral Restraint Forces for Z-Purlin Supported, Sloped Metal Roof Systems
This is a study to validate newly formulated design equations for the estimation of required lateral restraint forces in Z-purlin supported, sloped roofs under gravity loads.

RP01-2: Design of Cold-Formed Steel Plain Channels
An overview of the design procedures developed for laterally braced beams, columns and beam-columns of plain channels is provided.

RP01-1: Design of Bearing Stiffeners in Cold Formed Steel C-Sections
This research project was initiated by AISI to investigate the capacity of bearing stiffeners used in cold formed steel joists.

RP00-6: Effect of Anchorage and Sheathing Configuration on the Cyclic Response of Long Steel-Frame Shear Walls
This report presents the results of cyclic tests of 17 full-size, cold-formed steel-framed shear walls sheathed with oriented strand board, with and without openings.

RP00-4: Estimation of Restraint Forces for Z-Purlin Roofs Under Gravity Loads
The proposed restraint force design procedure applies to support, third-point, mid-span, quarter point, and third-point plus support restraints.

RP00-3: A Design Approach for Complex Stiffeners
This report presents a design approach for laterally braced cold-formed steel flexural members with edge stiffened flanges other than simple lips.

RP00-2: Web Crippling Data and Calibrations of Cold-Formed Steel Members
The objective of this study was to develop improved coefficients for predicting the web crippling strength expression currently used in the Canadian Standard.

RP00-1: Distortional Buckling of Cold-Formed Steel Columns
This study focuses on distortional buckling of members with edge-stiffened elements.

RP99-2: Monotonic and Cyclic Tests of Long Steel-Frame Shear Walls with Openings
This report presents the results of monotonic and cyclic tests of 16 full-size, cold-formed steel-framed shear walls sheathed with oriented strand board.

RP99-1: Design of Cold-Formed Steel Structural Members and Connections for Cyclic Loading (Fatigue)
The intent of this research report was to develop general design rules for the design of cold-formed steel members and connections subject to fatigue loading.

RP97-2: Additional Shear Wall Values for Light Weight Steel Framing
This report presents the results of 16 monotonic and 28 cyclic tests of flat strap X-braced walls and steel-sheathed shear walls.

RP97-1: Monotonic Tests of Cold-Formed Steel Shear Walls With Openings
Findings from this study indicate that cold-formed steel-framed shear walls are a viable alternative for residential construction in high wind and high seismic regions.

RP96-1: Shear Wall Values for Light Weight Steel Framing
The results of tests of 42 full-size, cold-formed steel-framed shear walls sheathed with plywood, oriented strand board and gypsum wallboard are presented.

RP92-1: Design Provisions for Cold-Formed Steel Columns and Beam Columns
This study covers research to develop an improved design approach for cold-formed steel columns and frames.

RP81-1: Fire Resistance Ratings of Load Bearing Steel Stud Walls With Gypsum Wallboard Protection
The results of a two-phase study to determine the effects of temperature on material properties are presented.