SPECIFYING STOCK COMPONENTS for …specifying stock components for architectural metal work ......

of 70©2013 ∙ Table of Contents

• About the Instructor • About the Sponsor • Ask an Expert

SPECIFYING STOCK COMPONENTS for ARCHITECTURAL METAL WORK

Architectural Metals, Railing Systems, and Engineering Information

Julius Blum & Co., Inc.P.O. Box 816

Carlstadt, NJ 07072Toll‐Free: 800‐526‐6293

Tel: 201‐438‐4600 (local NJ)Fax: 201‐438‐6003

Email: [email protected]: www.juliusblum.com

©2013 Julius Blum & Co., Inc. The material contained in this course was researched, assembled, and produced by Julius Blum & Co., Inc. and remains its property. Questions or concerns about the content of this course should be directed to the program instructor. This multimedia product is the copyright of AEC Daily.

START

This Online Learning Seminar is available through a professional courtesy provided by:

powered by

http://www.juliusblum.com/

https://www.aecdaily.com/


mailto:[email protected]



SPECIFYING STOCK COMPONENTS for ARCHITECTURAL METAL WORK

Julius Blum & Co., Inc.P.O. Box 816.Carlstadt, NJ 07072.

The course includes a discussion on: how to choose the best material for your job; available systems and their components; engineering data and the formulas to provide safe installations.

To ensure the accuracy of this program material, this course is valid only when listed on AEC Daily’s Online Learning Center. Please click here to verify the status of this course. If the course is not displayed on the above page, it is no longer offered.

This course is approved by other organizations. Please click here for details.

The American Institute of Architects ∙ Course No. AEC659 ∙ This program qualifies for 1.0 LU/HSW Hour.

AEC Daily Corporation is a Registered Provider with The American Institute of Architects Continuing Education Systems (AIA/CES). Credit(s) earned on completion of this program will be reported to AIA/CES for AIA members. Certificates of Completion for both AIA members and non‐AIA members are available upon request. This program is registered with AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

Presented by:

Description:

https://www.aecdaily.com/course.php?node_id=1744120&tabidx=viewcoursedetails&company=Julius+Blum+%26+Co.,+Inc.

https://www.aecdaily.com/course.php?node_id=1744120&tabidx=viewcoursedetails&company=Julius+Blum+%26+Co.,+Inc.

https://www.aecdaily.com/forums.php?node_id=1744120

https://www.aecdaily.com/faculty_bio.php?parent_id=1744120

https://www.aecdaily.com/sc.php?node_id=1468828&tabidx=corporate&company=Julius+Blum+%26+Co.,+Inc.



How to Use This Online Learning Course

• To view this course, use the arrows at the bottom of each slide or the up and down arrow keys on your keyboard.

• To print or exit the course at any time, press the ESC key on your keyboard. This will minimize the full‐screen presentation and display the menu bar.

• Within this course is an exam password that you will be required to enter in order to proceed with the online examination. Please be sure to remember or write down this exam password so that you have it available for the test.

• To receive a certificate indicating course completion, refer to the instructions at the end of the course.

• For additional information and post‐seminar assistance, click on any of the logos and icons within a page or any of the links at the top of each page.






Learning Objectives

At the end of this program, participants will be able to:

• Explain the reasons why stock components benefit high quality building projects and are cost effective.

• Detail how to choose a railing system and material to suit the needs of the project and surrounding.

• Discuss the importance of effective packing and handling measures for material shipping and storage as well as their ecological benefits.

• Discuss the reasons why metal suppliers should provide independent product testing and engineering information for their products.






An Overview of Architectural Metals, Alloys, and Finishing 6

Railing Systems and Components 19

Engineering Data: Elements of Sections, Railing Formulas, Problems and Solutions 52

In Summary 69

Table of Contents

Click on title to view






An Overview of Architectural Metals, Alloys, and Finishing






Trade Background and Information

For more than 100 years, architectural metal service centers have played an important role in stocking pre‐engineered components used in the fabrication of handrails and other decorative elements of structures. Because of their established relationships with foundries and mills, these distributors can make sure that high quality parts are available from stock for immediate shipment. And, by providing data on the structural properties of this material, the architect is able to design in conformance with national and local code requirements.






The Benefits of Purchasing Stock Components

There are numerous reasons why stock components are commonly used and/or specified by architects, contractors, fabricators, and building project teams.

• Large quantities available “off the shelf”.

• Quality products meet quality control.

• Products are designed and engineered to meet current codes.

• Complete systems aid in ease of design and installation (by an experienced miscellaneous metal fabricator).

• Installation drawings and details are supplied for all products .

• Cost advantages to purchasing prefabricated and pre‐engineered items .






Packing and Handling

A high quality prepared surface is important for the best visual properties, architectural performance, and long‐term durability. For these reasons, it is important that the selected supplier takes the measures listed below. Customers should expect:

In the warehouse:• Suppliers should use paper leaving to protect metal surfaces.• Stacked bundles are wrapped and crated for general protection.

For transport:• Heavy tri‐wall bundle wrapping protects the individual bar stock .• Steel strapping eliminates the possibility of bending.• Paper wrapping protects the surface from scratches and deflection.






Environmental Awareness

Metals: Recycled and Recyclable.The ever‐growing importance of protecting the environment and reducing waste extends to the metal industry as well. Architectural metals are largely composed of recycled material. Information on the recycled content of the material should be available for those that require LEED® certification.

Packing: Eco‐Conscious Packing.Using old newspapers as packing material, reusing storage boxes and bins, and recycling unused business forms into memo pads are examples of the small ways a business can continue to keep the environment in mind.






Metal Alloys for Architectural Metal Work

A number of common metal alloys are described as architectural metal. Each offers unique performance properties and visual characteristics, and is suitable for specific applications. Some of the most common architectural metal alloys include:

• Aluminum: 6063‐T52, 6063‐T832, 6061‐T6.

• Bronze: Alloy C38500.

• Stainless Steel: Alloy 304.

• Nickel‐Silver: Alloy C79800.

• Steel: Alloy C1010.

• Malleable Iron.

• Cast Iron.






Metal Alloy Interactions

When specifying a metal type for a job, the specifier should be aware of any possible interactions a metal will have with another metal, between metals and cement/lime mortar, and between metals and the environment.

• Aluminum should be coated with either a mechanical or chemical coating and should not be left unfinished against cement/lime mortar.

• Bronze/nickel‐silver left untreated will develop a patina, e.g. the Statue of Liberty. The speed at which the metals will patina is dependent on both the bronze alloy and the environment.

• Stainless steel is not affected by contact with other metals or by the environment.

• Steel will corrode if not properly protected by paint or other coatings.






Types of Metal Finishes

The finishes that are most commonly used on architectural metals can be classified into the following types:

• Mill Finishes: These are finishes applied by a basic rolling mill, the extrusion press, or a casting mold.

• Mechanical Finishes: These finishes are applied by the fabricator, and are the result of physically affecting the surface of the metal by some mechanical means.

• Chemical Finishes: These finishes (usually a pre‐finish) are applied by the fabricator, and they may or may not have a physical effect upon the surface of the metal.

• Coatings: These finishes are either formed by the metal itself by a chemical or electrical conversion process, or formed by application of added material applied by the fabricator or specialist.

NAAMM/NOMMA 500‐06, Metal Finishes Manual for Architectural and Metal Products is an excellent reference for metal finishes and can be found here: http://www.naamm.org/amp/amp_technical_literature.aspx Accessed May 2013.

http://www.naamm.org/amp/amp_technical_literature.aspx






Types of Metal Finishes

Source: NAAMM/NOMMA 500‐06, Metal Finishes Manual for Architectural and Metal Products, p.V. http://www.naamm.org/amp/amp_technical_literature.aspx Accessed May 2013.

Finish Aluminum Copper Alloys Stainless Steel Carbon Steel and Iron

Mill (as supplied) X X X X

Mechanical X X X ‐

Chemical X X ‐ ‐

Coatings X X X X

The following table references the previous two slides and further matches metals with their finishing options.

http://www.naamm.org/amp/amp_technical_literature.aspx






Selecting the Best Material for Your Job

When designing and selecting material for your project, there are a few criteria to consider:

1. Job location: As metals interact with the environment, the location (e.g. coastal, indoors, outdoors) of the job is important in determining the type of metal specified.

2. Fabricator expertise: Every job, with the exception of a non‐weld system (slide 26), requires an experienced miscellaneous metal fabricator. It is important to check with them first to make sure they have worked with/can handle the material you have specified.

3. Cost: The relative price of specific metals may be one of the determining factors in choosing the metal for a specific application.Metal prices are constantly fluctuating, and prices are determined by market values.

4. The look: Regardless of the information above, the architect or owner may wish to pick the metal based on color to suit the look and feel of the job.

*Always make sure there is an experienced metal fabricator on the job. Your material supplier can suggest the names of fabricators to ensure quality of work.






Architectural Metals and Alloys

Dylan’s Candy Store, New York, NY.Stainless Steel: Alloy 304.

Office Building, Scarsdale, NY.Stainless Steel: Alloy 304.

The photos below illustrate two stainless steel jobs, completed by an experienced metal fabricator. It is always important to make sure the fabricator designated to the job is capable of producing the desired product.







Library, Phoenix, AZ.Aluminum: Alloy 6063‐T52 & Alloy 6061‐T6.

Hospital, Huntsville, AL.Nickel‐Silver: Alloy C79800.

The photos below illustrate two jobs, aluminum and a nickel‐silver, completed by an experienced metal fabricator. It is always important to make sure the fabricator designated to the job is capable of

producing the desired product.







Office Building.Bronze: Alloy 385.

Malleable Iron Component.

The photo, lower left, illustrates a bronze job completed by an experienced metal fabricator. The photo, lower right, is an example of a high quality (note the detail in the casting) malleable iron component. It is always important to make sure the fabricator designated to the job is capable of producing the desired product.






Railing Systems and Components






Glass Railing System and Components

Glass railing is a system comprised of metal railing components for use with ½" or ¾" tempered glass panels as structural balusters.

A readily available system complete with the shoe mouldings, a variety of top rails/mouldings (in different metals) and components has been designed for use with glass.

**It is always important to make sure the system has been load tested by an independent contractor and that a test report can besupplied.

Glass rail installations, as well as many other railing applications, require that a guardrail have a handrail included as well. Most building codes differentiate between handrail and guardrail. Handrails are generally defined as being used for guidance and support, while the purpose of guardrails is to resist accidental falls.

*It is always important to check with your local codes authorities.







Readily available with stock components for glass railing:

Glass Mounting: Resilient setting blocks support and cushion glass panels as they are inserted in the shoe. Space is allowed for plumbing and setting of glass.

Handrail Assembly: Vinyl insert protects the top edge of the glass panel and fits closely inside the handrail

moulding. The specifier selects the sealant.






Readily available with stock components for glass railing:


Handrails and Tubing: Top mouldings are available in several shapes and sizes, and are suitable for finishing

and polishing. Mechanical connections may be preferred to avoid reductions in allowable design

stresses that are caused by welding joints.

Corner Bends, Miter Corners, End Caps: End caps are available, and different styles of elbows can be

attached to the handrail and used as wall connectors.







Chronicle Books, San Francisco, CA.Stainless Steel: Alloy 304.

American Girl, Natick, MA.Stainless Steel: Alloy 304.








Boston World Trade Center, Boston, MA.Stainless Steel: Alloy 304.

Corporate Headquarters, Scottsdale, AZ.Stainless Steel: Alloy 304 .







Pipe Railing System (fabricated without welding)

There are a variety of pipe railing systems available. One type of pipe railing system is easy to assemble and can be fabricated quickly, often on‐site, without welding. Components slip together and are joined by concealed mechanical fasteners at intersections and by epoxy structural adhesive at splice joints. Pipe and fittings may be provided in a variety of metals. Mechanical connections avoid the reduced allowable design stress effect that welding would have on the material.

*It is always important to make sure that the material installed meets local and national safety standards and guidelines when installed in accordance with data and instructions provided by the supplier.

Office Building, Scarsdale, NY.Stainless Steel: Alloy 304.







Mechanical Connections: Structural adhesive, stainless steel machine screws with lock washers, and threaded tubular rivets provide positive connections at joints.

Continuous Posts and Rails: Posts and top rails run in continuous lengths, providing a system that is inherently stronger than one with cast tee and cross connections.







Range of Fittings: A suitable fitting is available for practically any stair or ramp railing condition. Adjustable handrail brackets and ramp rail tees are recommended for

unusual ramp or stair angles.

Mounting Options: Posts may be embedded in floor slab with a cover flange, surface mounted with a heavy‐duty floor flange, or side mounted on fascia or stringer by means of a fascia flange. A reinforcing insert is used at the base of the post for added strength and stiffness.







ASCAP Building Entrance, Nashville, TN.

Commercial Building Entrance, Wilmington, DE. United Center for Cerebral Palsy, Islip, NY.

A non‐weld pipe railing system can be an effective, durable rail type for commercial and institutional buildings. It can be assembled quickly, on‐site, and is relatively cost effective.






Pipe Railing System

Sun Valley Music Pavilion, Sun Valley, ID.






Post and Panel System (no welding required)

Other non‐weld railing systems are also available that do not have circular shapes. One of them is often called a post and panel system.

A complete selection of fittings is available for this type of system. Self‐aligning wall, post, and mounting brackets are usually recommended for unusual ramp or stair angles. Handrails may be mounted using flat bars and channels, joined with non‐welded corner bends, or closed with end caps. A wide range of cover flanges, fascia flanges, reinforcing bars, and post caps are also available.

Business School, Jackson State University, Jackson, MS.






Post and Panel System (no welding required)

A full range of components are available in aluminum, bronze, nickel‐silver, and stainless steel to meet virtually any installation requirement. Posts and handrails may be combined with a variety of post, wall, and fascia

brackets to achieve a wide range of design alternatives, while meeting code and other regulatory requirements.

• Handrails.

• Precut Posts.

• Extensions.

• Brackets.

• Flanges.

• Plugs.

• Caps.






Weld‐Free Post and Panel Railing System

Handrails and Tubing: Top mouldings are available in several shapes and sizes. Check with the supplier.

Full Range of Fittings: A complete selection of fittings are available. Self‐aligning brackets are recommended for

unusual ramp or stair angles. A wide range of cover flanges, fascia flanges, reinforcing bars, and post caps are also

available.







High School, Wilder, KY.Library, Phoenix, AZ.

The photos below illustrate completed jobs utilizing the weld‐free post and panel system.







High School, Leander, TX.Indiana Wesleyan University, Greenwood, IN.

The photos below illustrate completed jobs utilizing the weld‐free post and panel system.






Traditional Railing Components

Traditional systems can be ornate or simple. Major profiles are commonly extruded or drawn, while fittings are machined or cast. It requires a high level of fabrication expertise to join a casting to an extrusion and not show any joint seams.

Handrail mouldings and components are carried in stock in a variety of metals. Railing components include posts and spindles, volutes, lateral scrolls, lamb’s tongues, post caps, collars and finials. The system is designed to mix and match fittings and mouldings. While the handrail must meet local codes and engineering regulations, architects and fabricators have many options in the design.

The following slides showcase stock components in traditional shapes and profiles, which help make intricate, classical metalwork the most cost effective option.

Private Residence.







Handrail Mouldings

Golf & Country Club, Newport Beach, CA.Muttontown Golf & Country Club, East Norwich, NY.







Handrail Fittings

Pennsylvania Judicial Center, Harrisburg, PA.Beverly Hills Montage Hotel Beverly Hills, CA.

Golf & Country Club, Newport Beach, CA.







Post Caps, Collars, Finials, Balusters, Bases, Flanges, Post and Spindle Fittings







Starting Posts.

Ornamental Valences. Spindles.







Beverly Hills Montage Hotel Pool and Spa, Beverly Hills, CA.







Private Residence. Private Residence.






Treillage and Ornamental Railing Panels

Malleable iron railing panels are used to provide architectural details on both stairs and straight runs. Panels should be designed to meet current code requirements.

Treillage panels are double faced and superbly detailed. Because they are malleable iron, they may be welded and bent cold and will not break or shatter in

the course of normal handling.







Ornamental collars are a cost effective way of providing details to a stair, fence, or gate. A wide variety of design options are possible using a combination of

ornamental collars.

Aluminum castings are recommended where it is important to keep weight at a minimum, as in gates or removable screens. Otherwise, malleable iron castings are

preferred for their strength and resistance to breakage.







Ornamental Railing Panels.

Ornamental Collars.

Treillage and Ornamental Railing Panels.

Ornaments.







Private Residence. Private Residence.






Handrail Brackets

Handrail brackets are used in many rail applications. They are designed for use as wall brackets, post brackets, center rail, and vertical mounting brackets.

Handrail brackets are designed to meet or exceed accepted safety standards and have been laboratory tested. Test reports should be available upon request from your supplier.

Center Post Bracket: Stainless Steel.






Self‐Aligning Wall Brackets

Wall Brackets: These are available in a variety of finishes and also self‐align to any slope when wall mounted. Once the concealed wall

attachment is made, the bracket yoke which attaches to the handrail rotates freely until the chosen handrail is properly aligned. Various

styles are available to coordinate with different handrail styles and with pipe railings.

Post Brackets: These are available in a selection of metals and self‐align to any slope when post mounted. They are adaptable for drywall when

the post screw is replaced with a lag screw and used with proper backup.






Handrail Brackets

Vertical Mounting Brackets: The mounting brackets are useful for mounting handrails vertically as in an elevator cab or hospital corridor. These brackets are also used with wood handrails. They are suitable for

mounting handrails on top of a parapet or knee wall. Adapters are available to permit attachment to pipe or round tube.

Cast/Stamped/Extruded Brackets: These brackets have a more traditional style and are used in a multitude of applications. The various

styles allow for concealed fastening or attachment with a single mounting bolt through the wall flange center. Specify this bracket for an

attractive and durable finish.






Tubing, Bars, Shapes and Elevator Cab Components

A large selection of tubing, bars, and shapes are sold in aluminum, bronze, stainless steel, nickel‐silver and steel. The stock sizes of tubing bars and shapes are selected to especially meet the requirements for ornamental and miscellaneous metal work. Material is sold mill finish and is suitable for polishing.

Shapes are extruded to high tolerances and have the sharp corners required for architectural work. Angles and tees are used frequently in dropped ceilings and are also used in areas of elevator cabs. It is important that all extrusions are handled with great care to assure that the product is well suited for architectural finishing.






Elevator Cab Components

An entire group of components are available for use in the assembly of elevator cabs. These include, but are not limited to, door thresholds and saddles, single and double speed sills, mouldings, handrail brackets for vertical use, and tubing bars and shapes. These items are typically available in aluminum, bronze, nickel‐silver, and stainless steel in a variety of sizes for many elevator applications.






Elevator Cab Components

Tubing Bars and Shapes.

Elevator Cab Handrails and Brackets.

Elevator and Door Saddles.

Thresholds and Door Saddles.






Engineering Data: Elements of Sections, Railing Formulas, Problems and Solutions






Engineering Data

Availability of complete structural information enables architects and designers to make proper use of a manufacturer’s component systems to provide safe, durable, handrail installations. The designer can engineer

installations to conform to specific building code loading criteria or can establish design requirements for a given installation on the basis of anticipated traffic exposure and types of use. The following slides illustrate the types of pertinent engineering data and information necessary for installation of safe railings. This information should

all be available in hard copy through the manufacturer.

The five major considerations for the structural designs of handrails are:

1. Structural loading criteria as established by governing building codes or special design requirements.

2. Properties of railing materials and allowable stresses for design.

3. Elements of sections for railing components.

4. Load, stress, and deflection relationships expressed as formulas for engineering design.

5. Proper attachment and sound supporting structure.






Structural Requirements

Structural requirements for railings are usually expressed in one of two ways, depending on governing codes and regulations. Some of these specify an applied loading distributed uniformly along the rail while others specify loading concentrated on the top rail. The designer should consult the governing codes, local ordinance, project specifications, and regulatory authorities to determine specific structural requirements for compliance.

An excellent source of design load requirements can be found in ASCE/ANSI 7 Minimum Design Loads for Buildings and Other Structures, published by the American Society of Civil Engineers.






Allowable Stresses

To provide adequate safety factors, the engineering profession assigns to each material an allowable design stress which is usually expressed as a specific fraction of minimum yield, or as a smaller fraction of minimum ultimate

strength. Allowable stresses vary with the composition and temper of the material and also, to some degree, with the kind of shape and the direction of stress.

Yield strength is the point of stress (in pounds per square inch) at which material fails to return to its original position after the stress has been removed, and takes a permanent set. Minimum yield is defined as the test value exceeded by 99% of a large number of specimens. For non‐ferrous metals, the yield point is arbitrarily defined as the point of stress at which permanent set is a specific fraction of 1% of the length of the test piece (0.2% offset as shown to the right or 0.5% elongation). Ultimate strength is considerably higher (see graph).

STR

ESS

(lb

s./

sq.i

n.)

0.2% of GAUGE LENGTH

STRAIN (inches/inch)

Minimum Yield

Typical Yield

Minimum Ultimate

Typical Ultimate

Allowable Stress






Loading Diagram and Symbols

w* = Uniform horizontal loading, perpendicular to the rail (lb/ft).

L = Span between centerlines of posts or brackets (in.).

P = Horizontal force, perpendicular to rail applied at top of post (lb).

FH = Horizontal force, perpendicular to rail at any point along the railing (lb).

FV = Vertical force, perpendicular to rail at any point between posts (lb).

h = Height of post. Distance from point of load application above top of

attachment (in.).

h1 = Distance from top of post attachment to top of reinforcing insert (in.).

M = Bending moment (in.‐lb).

f = Unit stress (psi).

fs = Allowable fiber stress for design (psi).

Sx & Sy = Section modulus about the x‐ or y‐axis respectively (in3).

lx & ly = Moment of inertia about the x‐ or y‐axis respectively (in4).

k = Stiffness of member.

K = Bending moment constant.

c = Distance from the neutral axis to the extreme fiber of any section (in.).

E = Modulus of elasticity (psi × 106).

Δ = Deflection (in.).

R = Stiffness ratio.

Pf = Load proportion factor.

Fr = Reaction factor (psi).

* Values for w (uniform load in lb/ft) converted to lb/in by dividing by 12

Familiarity with these standard symbols and design variables will enable architects, fabricators, and contractors to better specify and install safe, durable railings.






Key Terms

Section Modulus ‐ a geometric property for a given cross‐section used in the design of beams or flexural members.

Allowable Design Stress ‐ a design philosophy civil engineers use to ensure the stresses developed in a structure due to service loads do not exceed the elastic limit.

Applied Bending Moment ‐ exists in a structural element when a moment (the perpendicular distance from a point to a line or a surface) is applied to the element so that the element bends.

Moment of Inertia ‐ a measure of an object’s resistance to changes to its rotation.

Moduli of Elasticity ‐ the mathematical description of an object or material’s tendency to be deformed elastically when a force is applied to it.

Maximum Allowable Deflection ‐ the maximum permissible deflection value where no reinforcement is necessary.






Bending Moments and Stresses

Determination of bending moments and stress in structural railing members follows conventional engineering design procedures. The resisting moment—calculated from the Section Modulus (S, which equals I/c) and Allowable Design Stress (fs)—must equal the Applied Bending Moment (M).

This translates into railing formulas as described on the next two slides.

Please remember the exam password FORMULAS. You will be required to enter it in order to proceed with the online examination.






Connections between posts and rails are assumed to be free to pivot, although in practice the rail post connection is normally not a pivot. Distribution of loads through multiple spans decreases maximum bending moment in horizontal members. The effect of different numbers of spans may be taken into account by varying the Bending Moment Constant (K). Calculation of Unit Stress (f) and Length of Span (L) are accomplished by

using the following formulas:

Note: Values of K are defined based on the maximum bending moment developed under various numbers of spans.

Bending Moments and Stresses: Rails

1. For uniform vertical or horizontal loads (w): 2. For concentrated loads (F) applied at mid‐span:






Bending Moments and Stresses: Posts

Posts act as vertical cantilever beams in resisting horizontal thrust applied at the top rail. Bending moment produced by horizontal thrust normally controls design, and post spacing may be calculated using the following

equations.

1. For uniform horizontal loading (w):

2. For concentrated horizontal loading (Fh): When concentrated loading is specified, the horizontal load on the top rail is distributed among several posts adjacent to the point of loading. The load distribution is a function of the relative stiffness of post and top rail and of the number of spans in the railing. This calculation will show what proportion (Pf) of the total load any one post may have to sustain. To the extent that it is less than 100%, it will justify the use of lighter and more economical construction. The following equations applies:






Internally Reinforced Posts

The load‐carrying capacity of a post with reinforcing insert is limited by the allowable fiber stress at one of three points.

1. The post at the top of the insert, above which it is not reinforced.

2. The insert at its base, at the highest point of its attachment to the supporting structure.

3. The post at the same point of attachment.

The lowest of these three loading limits controls design for the combined post and reinforcing insert. Insert

Floor

Point of Attachment

P

h

h1






1. Post at top of insert:

Moment in post (top of insert) : Fiber stress in post (top of insert): Loading limit:

At the point of contact between the railing post and the reinforcing insert, the deflection of each is assumed to be the same, but the resisting force of each is a function of its Moment of Inertia (I) and Modulus of Elasticity (E). The resultant combined Reaction Factor (Fr) at the top of the insert is determined as follows:







The loading limits for points 2 and 3 are then determined as follows:

2. Insert at base:

Moment in insert: Fiber stress in insert: Loading limit:

3. Post at base:

Moment in post: Fiber stress in post: Loading limit:







When two sections of the same metal are combined by being fastened together to form a handrail (e.g. a steel moulding mounted on a steel channel), the sections develop the same deflection under load but act

independently about their respective neutral axes.

Ia and lb are the moments of inertia of the two sections. Since the Section Modulus (S) equals I/c, the combined value for S of the two sections would be:

In the railing formulas, substitute the above equation for the value of S whenever combined sections of the same material are used.

Combined Handrail Sections

Steel handrail with steel channel.






To compute the loading of combined sections of dissimilar materials (e.g. a bronze handrail mounted on a steel channel) calculations involve the determination of the relative portion of the load carried by each section. The load distribution is a function of the relative stiffness of the two sections, which is determined by the Moments

of Inertia (I) and their Moduli of Elasticity (E). The distribution of the total load between two sections is determined as follows:

1. Load carried by A:

2. Load carried by B:

Individual calculation to determine the fiber stress for each material, using the load portion of each section, will then determine which section controls design: namely, the section giving the lesser result.

Combined Sections of Dissimilar Materials

y

A

B

y

xa

xb

c xa

c xb

B TotalLoad TotalLoadCarriedbyA






Excessive deflection of a railing under load, even though it meets strength requirements, will give the user a feeling of insecurity and may cause tripping or stumbling. Lateral deflection of posts or vertical deflection of

horizontal rails under load are computed as follows—these formulas must be used with caution:

1. For posts without reinforcing insert:

2. For posts with reinforcing insert of similar or dissimilar material:

Deflection Considerations






3. For rails (concentrated load, F):

4. For rails (uniform load, w):

There are few, if any, regulations or code requirements limiting deflection in a railing, but ASTM has put forth the following criteria regarding Maximum Allowable Deflection (Δmax) in their specification E985.

In many instances, the anchorage of the railing to the floor, tread or fascia is subject to a degree of rotation which will add an indeterminate amount to the deflection on the post and rail. Anchorage and supporting structure must be as secure and rigid as possible.

Deflection Considerations

For horizontal load at mid‐span:

For horizontal load at top of post:

For vertical load at mid‐span:






Sample Problem and Solution

Determine required section modulus of post requirements:• Concentrated load, F = 200 lbs.• Railing height, h = 42 in.

Material specified:• Post: Steel tubing• Allowable stress, fs = 16,800 psi

Determine:• Section modulus, S, and select a suitable section• Resisting bending moment, M(resisting) = fs × S• Applied bending moment, M(applied) = F × h• M(resisting) must equal M(applied)






In Summary

The stock component architectural metal supplier should be able to provide material properties, elements, structural loading criteria, and other engineering design information for all of their products. This information should be sufficient for the engineering and fabrication team to show compliance with governing building codes

or special design requirements.

As reiterated throughout the course:It is always the responsibility of the designer/architect to acquaint themselves and comply with the various codes and regulations that govern each product. The supplier should be able to provide test results, engineering data,

and installation instructions for their material.






Conclusion

©2013 Julius Blum & Co., Inc. The material contained in this course was researched, assembled, and produced by Julius Blum & Co., Inc. and remains its property.

Questions or concerns about the content of this course should be directed to the program instructor. This multimedia product is the copyright of AEC Daily.

If you desire AIA/CES, state licensing or CE credits for another organization, please click on the button to commence your online examination. A score of 80% or better will allow you to print your Certificate of Completion; you may also go to your AEC Daily Transcript to see your completed courses and certificates.

For additional knowledge and post‐seminar assistance, click on the Ask an Expert link above.

If you have colleagues that might benefit from this seminar, please let them know. Feel free to revisit the AEC Daily website to download additional programs from the Online Learning Center.

Exit

Click Here to Take the Test

powered by


https://www.aecdaily.com/course.php?node_id=1744120&tabidx=taketest&company=Julius+Blum+%26+Co.,+Inc.

http://aecdai.ly/aeccl

https://www.aecdaily.com/




SPECIFYING STOCK COMPONENTS for …specifying stock components for architectural metal work ......

Documents

Transcript of SPECIFYING STOCK COMPONENTS for …specifying stock components for architectural metal work ......