POSSIBLE FUTURE TRENDS IN COLD FORMED STEEL

OBJECTIVES ¥ PREDICTIONS -- RATHER A WISH LIST FOR DEVELOPMENTS ¥ HOPEFULLY TO STIMULATE DISCUSSION AND THINKING ¥ SOME PREDICTIONS FOR THE NEAR AND DISTANT FUTURE

“I THINK THERE IS A WORLD MARKET FOR MAYBE FIVE COMPUTERS,” THOMAS WATSON, CHAIRMAN OF IBM, 1943

“THERE IS NO REASON ANYONE WOULD WANT A COMPUTER IN THEIR HOME,” KEN OLSON, PRESIDENT, CHAIRMAN AND FOUNDER OF DIGITAL EQUIPMENT CORP., 1977

COLD-FORMED STEEL PREDICTIONS LESS SPECULATIVE ¥ STEEL HAS BEEN AROUND FOR A LONG TIME ¥ IRON AGE STARTED ABOUT 700 B. C. ¥ COLD-ROLLING STEEL GOES BACK ABOUT 120 YEARS ¥ APPLICATIONS IN PRINCIPLE SIMILAR TO THOSE 50 YEARS AGO

POSSIBLE FUTURE DEVELOPMENT TOPICS l MATERIALS l FORMING TECHNIQUES l CONNECTIONS l APPLICATIONS l CONSTRUCTION l ENGINEERING AND SPECIFICATIONS

MATERIALS TREND TOWARD HIGHER STRENGTH

MATERIALS LAMINATES TO IMPROVE : l STRENGTH l REDUCE WEIGHT l ACOUSTIC PERFORMANCE

MATERIALS l 30% INCREASE IN ELASTIC MODULUS TRANSVERSE TO ROLLING DIRECTION l ADVERSE EFFECTS IN LONGITUDINAL EFFECTS

MATERIALS l ADJUST YIELD TO ULTIMATE RATIOS (BETTER EARTHQUAKE RESISTANCE)

MATERIALS l BETTER CORROSION RESISTANCE l INCREASED USE OF STAINLESS STEELS l 12% Cr STEELS (NO NICKEL) BEING USED IN JAPAN IN HOUSING – SURFACE NOT SHINY, SOME RUST BUT AT MUCH SLOWER RATE

MATERIALS BETTER FIRE RESISTANT STEELS - LESS CREEP WHEN SUBJECTED TO HEAT

CF TECHNIQUES - HYBRID SECTIONS higher yield stress flange seamed and clinched lower yield stress web

CF TECHNIQUES - WEB STIFFENERS Embossed webs Cold worked web and flanges

CF TECHNIQUES EXPANDED USE OF AUTOMATIC FABRICATION LINES, SUCH AS FOR TRUSSES, WALL SUBASSEMBLIES

CF TECHNIQUES INCREASED USE OF ROLLING COMBINED WITH HIGH FREQUENCY WELDING IN ONE OPERATION

CF TECHNIQUES INCREASED USE CUTTING AND SEAMING ON PARTS OF SECTIONS TO FACILITATE CONNECTIONS (NON-PRISMATIC SECTIONS)

CF TECHNIQUES

CONNECTIONS

REPLACEMENT OF LIGHTER HOT- ROLLED STEEL MEMBERS WITH COLD ROLLED STEEL MEMBERS

APPLICATIONS - HOUSING l US ANNUAL CONSTRUCTION $415 BILLION. l ABOUT $165 BILLION, OF THIS IS IN THE RESIDENTIAL l POTENTIAL FOR STEEL IN THE ANNUAL 8.4 MILLION TONS. l NOTE: AUTOMOBILE INDUSTRY USES 3.5 MILLION TONS.

APPLICATIONS - HOUSING RESIDENTIAL MARKET Target 2002

APPLICATIONS - HOUSING Steel framing, joists, trussesResidential steel roofing 1994Target Target 2002

APPLICATIONS - HOUSING MOTIVATIONS FOR USE OF STEEL l STABLE STEEL PRICES VS FLUCTUATING TIMBER PRICES l DWINDLING TIMBER SUPPLIES l CONCERN FOR ENVIRONMENT l HIGH STRENGTH TO WEIGHT RATIO l DURABILITY

APPLICATIONS - HOUSING 50 TREES 6 JUNKED CARS

APPLICATIONS - HOUSING

l An old idea whose time appears to have come l Steel alone or in combination with other materials - a suitable material for residential applications l Worldwide interest and development

CONSTRUCTION l WORKERS LESS SKILLFUL l MANAGERS MORE EDUCATED BUT NOT FROM THE TRADE l CONSTRUCTION MORE TECHNICAL BUT SIMPLER TO PUT TOGETHER

CONSTRUCTION l THREE DIMENTIONAL DRAWINGS AND VIRTUAL REALITY TO REPLACE DRAWINGS IN THE FIELD l MORE OF THE STRUCTURES TO BE PRODUCED IN FACTORIES AND ASSEMBLED IN THE FIELD

TOUCH MEMORY

l DRAWINGS OF ASSEMBLY ATTACHED TO THE MEMBER l LIMITATIONS OF USE ATTACHED TO THE STRUCTURES - FOR EXAMPLE: RACK FOR A CERTAIN CONFIGURATION OR EARTHQUAKE ZONE l MANY OTHER USES

ENGINEERING AND SPECIFICATIONS l EFFORTS TO IMPROVE SPECS l SIMPLER APPLICATIONS SUCH AS RESIDENTIAL BUILDINGS l COMPLEX HIGHLY OPTIMIZED APPLICATIONS l UNIFICATION OF HR AND CR SPECS

ENGINEERING AND SPECIFICATIONS l SIMPLER APPLICATIONS SUCH AS RESIDENTIAL BUILDINGS l SIMPLER RULES FOR DESIGN AND MEMBER SELECTION l STANDARDIZED MEMBERS l SIMPLIFIED SPECIFICATIONS

ENGINEERING AND SPECIFICATIONS l COMPLEX SHAPES REQUIRE COMPLEX ENGINEERING ANALYSIS AND DESIGN l USE OF FINITE ELEMENT AND OTHER TYPES OF COMPUTER ANALYSIS WILL INCREASE GREATLY AND WILL BE ACCEPTED WIDELY

ENGINEERING AND SPECIFICATIONS l SPECS NEED TO ACCEPT COMPUTER ANALYSIS l TO CALCULATE CRITICAL STRESSES l TO CALCULATE ULTIMATE LOADS l SPECS TO REFLECT l FABRICATION TOLERANCES, l IMPERFECTIONS, l MATERIAL PROPERTIES, RESIDUAL STRESSES l COMPUTER PROGRAM ACCEPTANCE GUIDELINES NEEDED

PRESENT EFFECTIVE SECTION APPROACH

PROPOSED DIRECT STRENGTH APPROACH

KEY TO THE FUTURE l POSSIBILITIES LIMITED ONLY BY OUR IMAGINATION l DEVELOPMENTS WILL NOT HAPPEN WITHOUT ENGINEERING l INDUSTRY MUST PROVIDE LONGER TERM VISION l RESEARCHERS MUST WORK WITH THE INDUSTRY

CONCLUSIONS l DWINDLING TIMBER SUPPLIES l RECYCLABLE ENVIRONMENTALLY FRIENDLY MATERIAL l POSSIBILITIES FOR OPTIMIZATION l ROLLNG THICKER SHEETS - REPLACE MORE HOT- ROLLED APPLICATIONS l INCLUDE COMPUTER SOLUTIONS IN SPECS