Composite Section Modulus

Office buildings. ANALYSIS OF REINFORCED CONCRETE BEAMS BY THE EQUIVALENT SECTION METHOD Mauro Schulz Maria Paola Santisi d'Avila Summary This research investigates the analysis of reinforced concrete beams subjected to combined axial load, bending moment and shear force. Whoops! There was a problem previewing /index. How prepared are you? Do you have a sessional coming up? Is the end of sem exam already giving you jitters? Be it to secure high marks in your college exams, study for a professional exam or prepare yourself before a job interview, Magic Marks helps you achieve maximum success. Yc = the distance from composite beam centroid to the deck slab top most fiber, inches Sc = the compression Section Modulus, cin St = the tensile Section Modulus, cin. The potential strain energy stored in a beam during elastic deformation is. Zx is similar to the Section Modulus of a member (it is usually a minimum of 10% greater than the Section Modulus) (in3) The Nominal Moment will be modified by the Safety Factor (Ωb) to become:. I beam section properties calculator has been developed to calculate the sectional properties of structural I beam. 10 x 2 = 60. Using the "Beam Deflection - Single point Load Supported Two Ends" I calculate for this tube in Aluminum at 5' long with a 170 pound load in the center. The composite shaft, consisting of aluminum, copper, and steel sections, is subjected to the loading shown. member length, G shear modulus (use GGLR LT, or ap-proximate G by EL/16 if measured G is not available), and K a cross-section shape factor. 36 ksi); the difference between this calculated E c value and the experimental result obtained for the composite sample E c = 3. The FRP honeycomb sandwich panels we produce is made of FRP (fiberglass reinforced plastic) sheet as surface and aluminum honeycomb in the core. You can enter. 1 General. The type of construction envisaged is shown in Fig. Performex is a light to moderate-duty weatherable, vinyl sheet pile that is ideal for resisting corrosion in salt water conditions. I don't know exactly how G' is determined, but the reason G' is used instead of the typical steel shear modulus is because G' accounts for warping and fastener pattern. This section contains a review of tests done on beam-and-slab bridge systems in which unintended composite action was considered. If the axis is located in the web of the girder, (D. 1 Background 2-71. Cross section shapes like rectangular, square, circular, Isection and T, composite section etc. 2) Yes, for Composite Steel-I section generated in MIDAS Civil the torsional resistance of the slab is taken with a reduction of 50% as (bd^3)/6 rather than the value for a single thin rectangle. typical steel modulus of elasticity, modulus young polimer, aluminum modulus of toughness, calculation young modulus of rock, elastic modulus of concrete, modulus of elasticity of concrete and steel composite section, how to calculate mill modulus, bulk modulus of crude oil, shear modulusproblems, strand modulus. See Composite Deck-Slab Strength Web Based Solutions for alternate slabs or LRFD design. 0 = E W Q W + E S Q S. 6] recommends the stress-strain relationships of the materials shall be taken into account. The calculated parameters are cross section area, mass, second moment of area, section modulus, radius of gyration and CoG. Attard CVEN2301 Mechanics of. USE OF THE BRITISH STANDARD 3. Over a 40 year period, United Steel Deck, Inc. Durable construction FRP such as fibreglass sections and beams enhances the strength of the entire framework as well as infrastructure. Our honeycomb composite panel laminated by fiberglass sheet is a low cost solution for honeycomb composite products, with the cost ranging from 17USD to 28USD per square meter only. of section Once the static calculation is done and section modulus, pile length as well as steel grade are defined, it has to be checked, whether length of pile and section modulus are adequate for installation in the given soil conditions 10 Hard 30 22 6 Driving conditions Normal Easy AZ 25-800 AZ 40-700N AZ 30-750 AZ 50-700 Length (m) 26 18. Section modulus (Z) is defined by I=Moment of Inertia Ymax=distance from the Neutral axis. p = section modulus of composite section with respect to top of com-posite slab (ins) Stop,, e'us, = section modulus of composite section with respect to top of deck panel (in. REINFORCED CONCRETE Slide No. Current table represents European standard I sections, IPE beams with parallel flange, specifications, properties, dimensions. Often, composite crossarms are twice the strength and half the weight of their wood counterparts. Samuel Easterling2 SUMMARY Two procedures for calculating the strength and stiffness of composite slabs based on a partial interaction model are introduced. composite beam. Design of composite steel and. The strength of sheet piling to resist bending is a combination of the shape of the section and the material out of which it is made. The strength of concrete is dependent on the relative proportion and modulus of elasticity of the aggregate. where SNC, SST and SLT are elastic section modulus for steel section alone, short-term composite and long-term composite sections, respectively (in. Structural hollow sections. Interior beam composite section properties. 5^2)/6 = 15. Using the data given below, determine the largest permissible bending moment when the composite bar is bent about a horizontal axis. RISASection calculates typical section properties for multi-material, built-up structural sections. specified publication 408 section 106. 04-6 thru -X. The program provides a range of standard sections and allows creating custom wood sections and built-up wood sections. o AASHTO uses resilient modulus (M r) as the measure of soil strength, accounting for seasonal variation in soil strength; o ODOT utilizes Group Index and correlates to California Bearing Ration (CBR). Also, for a fibrous composite material the following equation may be used: E2 = V f *E f + V m *E m where the properties are in the direction of local axis 2. Each shape can have it’s own material properties such as weight and modulus of elasticity, and it can either be composite or non-composite to the beam. In other words, how much something bends (strain) under a given load (the stress). Section modulus is a geometric property for a given cross-section used in the design of beams or flexural members. 2 WIRE RATINGS 4000 0. Linear Thermal. The strength design method in Section 6 of Australian Standard AS 2327. 812 3 Seff and V' h as Functions of the Percent of Composite Action (CA) from 25% to 100% Values for the horizontal shear, effective section modulus and effective moment of inertia are displayed in the. c = is the average of internal and external corner radii T, B, D, d, t and r areg iv nth scobl ( du ). Neglect the size of the collars at B and C. slab simply resting on few steel girders, the R. This Chapter is applicable to the use of composite repairs on site-specific offshore units such as FPSOs and FSOs. Section modulus: W: DIN 53293 [cm³/m] 1. Guaranteed Safe Reynobond is fully tested and environmentally safe, with building code approvals throughout the world. 2-2)where MD1 is moment due to factored permanent loads applied to the steel sectionalone (kip-in. 200 2100 606065230 3127860300 3126211114. 1 The design of composite bridges and other composite highway structures belonging to the Department of. 4 mm and a length of 205 mm. Yet, each individual wood cell is even more structurally advanced because it is actually a multilayered, filament-reinforced, closed-end tube rather than just a homogeneous, nonreinforced straw (Figure 3-2). 6 ksi (A36) • Using the flexure equation, – set fb=Fb and solve for S • Choose a section based on S from the table (D-35 and D-36) – Bold faced sections are lighter. The properties calculated in the table include area, centroidal moment of inertia, section modulus, and radius of gyration. Method of transformed Sections a. Linear Thermal. Bank (1989) developed a method to simultaneously determine the section Young's modulus and the section shear modulus by using Timoshenko's deflection equation. If you mean to a section made of composite material……. 1 General. I don't know exactly how G' is determined, but the reason G' is used instead of the typical steel shear modulus is because G' accounts for warping and fastener pattern. And it was a measure of a cross section resistance to bending about a certain axis. this is a great work !, indeed, any ordinary folks, engineers or non-engineers can make use of this software program calculator (beta) to check, verify and simulate his/her conceptual design works for any steel reinforced concrete house or apartment’s sectional member such as rectangular, i-beam, etc. section might also be used for composite construction when the upper and lower flanges are switched. Re: How to calculate section modulus on certain cross section of a solid part Create your drawing of your part and then create your Slice-Section views. We said that the area moment of inertia I, is equal to the integral over the r squared, or integral over the area of r squared. Cross section shapes like rectangular, square, circular, Isection and T, composite section etc. Composite members and some forms of composite systems have been used extensively somewhere around the world. • Composite (FRP vinylester resin) tie-back strip having ultimate tensile stress of 20,000 psi. 2) If the axis is located in the concrete slab, (D. This calculator gives the values of moment of inertia as well as maximum and minimum values of section modulus about x-axis and y-axis of T section. 52 cm 3 (Taking allowable stress f c or f t in bending = 1,650 kg per cm 2) Section modulus of two such sections = 30. Section properties calculators to calculate cross section area, second moment of area, section modulus, radius of gyration, center of gravity of the cross section and mass of a beam or column for standard profile types and geometric shapes. The location of the neutral axis (NA) is one of the most critical steps when solving for bending stresses in composite beams. If a composite beam is to be constructed without shoring, the section at the web opening should be checked for adequate strength as a non-composite member under factored dead and construction. Composite Decking (Trex Transcend and Trex Enhance) 1. Plastic section modulus. With CBeam, a composite beam section can be created and edited graphically using any combination of rectangle, triangle or I-beam shapes. The mechanism of redistribution of bending stress in a steel beam after the attainment of first yield is explained. See Composite Deck-Slab Strength Web Based Solutions for alternate slabs or LRFD design. it behaves as single unit for compression and extension against compressive and tensile stress. Job Title: COMPOSITE SLAB Worked Example - 1 Made by SSSR Date 14-05-00 Structural Steel Design Project Calculation Sheet Checked by PU Date 08-08-00 Check the adequacy of the continuous composite profiled deck slab with spans of 3. The utility of the section modulus is that it characterizes the bending resistance of a cross section in a single term. Within the elastic range below the proportional limit, this ratio is a constant for a given piece of wood, making it useful in static bending tests for determining the relative stiffness of a board. create composite action during stripping from the form, handling, and erection, but the shear transfer is not relied on to provide com- posite action for resisting service loads. Section Modulus – Composite Beam System Example The figure below illustrates the various components in our beam system. Deflections at this stage are calculated using elastic analysis, neglecting effects of shrinkage and by using the average cracked and uncracked second moment of area of the slab. 14 State of the Art of Precast/Prestressed Concrete Sandwich Wall Panels. The section modulus is a composite measure of bone strength in bending and in torsion , and it is proportional to the (R p 4 − R e 4)/R p, where R p represents the periosteal radius and R e represents the endosteal radius. The program provides a range of standard sections and allows creating custom wood sections and built-up wood sections. Young's Modulus or Tensile Modulus alt. Design a typical floor beam with 3 in. 2 Moment of Inertia - Composite Area Monday, November 26, 2012 Radius of Gyration ! This actually sounds like some sort of rule for separation on a dance floor. Section Modulus Z in3/ft 13 D790-03 Moment of Inertia I in4/ft EVERCOMP 26. 200 2100 606065230 3127860300 3126211114. In this section, a TC300 carbon/epoxy composite plate is taken as a research object, as shown in Figure 3. 2 discusses how the nominal strength of the composite section is determined. 6 Backfill Backfill material placed behind the sheetpile shall be free draining and restricted to GW, GP, SW,. This is a good place for a break. Concept of transformed or equivalent section of a RCC beam R. Calculates noncomposite and composite (for modular ratios n and 3n) section properties for steel I-girders with concrete deck. So, the section modulus is 2*(1. Manufactured according to standards : DIN 1025. The behavior of a beam with sandwich cross-section under a load differs from a beam with a constant elastic cross section. If a composite beam is to be constructed without shoring, the section at the web opening should be checked for adequate strength as a non-composite member under factored dead and construction. Specifically, although FRP materials exhibit very high strengths, the modulus of elasticity is relatively low compared to steel. Cross Section Properties Calculator Software This page lists the cross section properties calculated by ShapeDesigner SaaS software. If you mean to a section made of composite material……. Video created by 乔治亚理工学院 for the course "Mechanics of Materials III: Beam Bending". ) modulus of foundation (psi). To calculate composite seciton properties we have to know slab thickness, girder spacing, and modulus of elasticity of girder and slab. Section Modulus Calculator. The key to this case can be found in the record testimony of the president of Epic, Donald Landis. 5 in 4 ybc = distance from the centroid of the composite section to extreme bottom fiber of the precast beam = 64056. deck slab will take the superimposed load and live load by spanning between the steel girders and thus will transfer the loads on to the steel girders. If I have a composite beam or an T beam where the top of the T is of significantly higher stiffness than the vertical part. Section modulus (Z) Another property used in beam design is section modulus (Z). 8 Shear Modulus --- 106 psi 0. ASTM D-7032-04: Standard Specification for Establishing Performance Ratings for Wood-Plastic Composite Deck Boards and Guardrail Systems (Guards or. be expressed in terms of strain and Young's modulus Ee cC =+ee m E m V mf EV ff (5. Section properties for prestressed concrete double-tee (NEXT) beams have been added. It is the transformed second moment of area, Wt is the transformed section modulus and E is the elastic modulus. Part 1 General. loading are obtained by applying the concept of the modular ratio, n = EsiEc, where. In current international practice, CFT columns are used in the primary lateral resistance systems of both braced and unbraced building structures. Our B-Deck profile is usually used as a roofing product however, it has been supplied for siding and other architectural applications. Section modulus is a geometric property for a given cross-section used in the design of beams or flexural members. 3 References. (b) If the cross-sectional area is 250 mm2 (0. Reinforced Concrete Beam Concrete Beam 2 ©jkm Concrete Beam We will examine a concrete beam in bending A concrete beam is what we call a composite beam It is made of two materials: concrete and steel Concrete is also a composite 2 P 2 P. When possible, the program can automatically select the appropriate wood. The composite also has a high tensile strength to weight ratio. pultruded composite sheet pile panels with reduced or eliminated shear effect. Volume 1 Section 3 Chapter 3 BD 16/82 Use of The British Standard ELECTRONIC COPY - NOT FOR USE OUTSIDE THE AGENCY November 1982 PAPER COPIES OF THIS ELECTRONIC DOCUMENT ARE UNCONTROLLED 3/1 3. timbers and structural composite lumbers (LVL, PSL, LSL). parameler used for truss connecUons as defined in Section 9. To calculate composite seciton properties we have to know slab thickness, girder spacing, and modulus of elasticity of girder and slab. The gauge length of. This engineering data is often used in the design of structural beams or structural flexural members. with differing materials (modulus of Elasticity, E), are “laminated” together to form a. Modulus of Elasticity of Concrete. Composite Decking (Trex Transcend and Trex Enhance) 1. Therefore, plates are attached to the beams. The modulus of elasticity applies specifically to the situation of a component being stretched with a tensile force. Elastic section modulus about X neutral axis related to the top fiber: S x bot: Elastic section modulus about X neutral axis related to the bottom fiber: X right: Extreme right fiber from y neutral axis: X left: Extreme left fiber from y neutral axis: S y right: Elastic section modulus about Y neutral axis related to the right fiber: S y left. Plastic section modulus. Edgewise modulus of rigidity and pure edgewise modulus of elasticity properties of southern pine plywood and LVL specimens of different depths tested with central loading at three different spans but at the same span-to-depth ratio of 14. Generally, it supports floor or roof joists in simple span conditions or other secondary elements (purlins, wood trusses, etc. Section modulus: W: DIN 53293 [cm³/m] 1. 2b stipulates that the available compressive strength of a filled composite member need not be less than that specified for the bare steel member, as required by AISC Specification Chapter E. The composite shaft, consisting of aluminum, copper, and steel sections, is subjected to the loading shown. A homogeneous beam is one that is made of one material, such as, wood or steel. 14 State of the Art of Precast/Prestressed Concrete Sandwich Wall Panels. It assumes that the steel beam carries both live and dead loads and compensates for this by permitting a higher stress in the steel:. GRP Thickness Grades. Width of Sheeting Section 18” B Thickness. The procedures rely on elemental test results for interfacial. 85" 38 ULTIMATE LOAD PER WIRE (lbs) DEFLECTION PER 1000 (in) WEIGHT (lbs) 8. By continuous fiber-reinforced laminates, the following is assumed:. Young’s modulus is the ratio of the pressure on the object (stress) to the strain of the object. Plastic section modulus is the more uncommon form of plastic section modulus, and most general designs by engineers do not use it in their calculations. Smin = Minimum Section Modulus; Both the allowable bending moment and the section modulus are specified as per lineal foot or meter of wall. Method of transformed Sections a. 5m Allowable Bending Moment 6kNm Section Modulus 28412mm3 Characteristic Full Section Young’s Modulus* 34GPa Weight/Piece 13kg EZE Slider 0. Shear-Bond: Is the interlocking between a concrete slab and the composite steel deck. Therefore, plates are attached to the beams. Transformed-Section Method. Current table represents European standard I sections, IPE beams with parallel flange, specifications, properties, dimensions. The predesign charts have been developed for non- composite and composite beams in steel grades S355, S460 and HISTAR® 460. horizontal section c = largest distance from the neutral axis to the top or bottom edge of a beam d = calculus symbol for differentiation = depth of a wide flange section d y = difference in the y direction between an area centroid ( ) and the centroid of the composite shape ( ) DL = shorthand for dead load E = modulus of elasticity or Young's. We have also produced a spreadsheet that will calculate the cozzone shape factor for a symmetrical section of compound rectangular shapes. , , respectively. Preliminaries for octonion operation In this section we describe the operations on octonion ring and properties of octonion ring. The A, we found out had a finite for composite shapes and standard shapes the last time. Hot Rolled Steel - Composite Beam Design. Beam Cross Section : The NA can be determined from the equation. Young’s modulus is a very valuable property of matter and is used to characterize the stiffness of the material. s Elastic section modulus of steel profile [mm 3/mm] Z s Plastic section modulus of steel profile [mm 3/mm] β Stress exponent used in conjunction with soil stiffness [-] φ Angle of internal friction [º] γ m Soil material safety factor [-] γ n Safety class factor according to Eurocode [-] λ f Stiffness number [-]. integral wearing surface which is not included in the calculation of the composite section properties) Haunch depth = 4 in. centroid of the beam section. Consider a composite section as shown below subject to a maximum bending moment of 400 Nm. be expressed in terms of strain and Young's modulus Ee cC =+ee m E m V mf EV ff (5. member length, G shear modulus (use GGLR LT, or ap-proximate G by EL/16 if measured G is not available), and K a cross-section shape factor. This engineering calculator will determine the section modulus for the given cross-section. St = section modulus of non-composite section, extreme top beam fiber (in3) S tc = section modulus of composite section, extreme top beam fiber (in 3 ) y b = distance from the center of gravity of the non-composite section to the bottom of the. Ic = moment of inertia of composite section = 694599. 38M DEEP x 1. ALUCOBOND® PLUS is a composite panel consisting of two aluminium cover sheets and a mineral-filled polymer core. This is a good place for a break. is it true that the further a stiffness material is from the neutral axis the greater the effect on the overall stiffness is? is it possible to calculate a new flexural modulus. The Laminator by www. AB is supported on CD, without any connection between them and carries a uniformly distributed load of magnitude w. Units: The units are ‘Pascals’ after the late French physicist – Blaise Pascal. Now you have all the necessary tools for finding moments of inertia of composite areas. Also, for a fibrous composite material the following equation may be used: E2 = V f *E f + V m *E m where the properties are in the direction of local axis 2. Plastic section modulus. hc = total height of composite section = 62. Therefore, the engineer of record is encouraged to analyze the stresses induced into the sheet pile sections from concentrated loads. This allows for optimization of a beam's cross section to resist bending by maximizing a single parameter. The cross-sectional area and modulus of elasticity for each section are shown in the figure. Full section testing is based on a 3-point bend with simply supported end conditions (Reference The New and Improved Pultex® Pultrusion Global Design Manual Appendix for details). Instruments DMA2980). This method is an alternative to the preceding section. 05 x 10 6 kPa (442. It is available with either a poly-. It is a mathematical property of a section concerned with a surface area and how that area is distributed about the reference axis (axis of interest). 2 for encased composite columns cr thickness of concrete cover from center of longitudinal reinforcement to the edge of section in the plane of bending D overall dimension in the direction of buckling Ec elastic modulus of concrete Em modifi ed modulus of elasticity Fcr critical. In the figure to the left, I have collected the traditional, and some additional expressions, for the cozzone shape factor. If I have a composite beam or an T beam where the top of the T is of significantly higher stiffness than the vertical part. All that remains is to learn to use them on composite areas. deck slab will take the superimposed load and live load by spanning between the steel girders and thus will transfer the loads on to the steel girders. The titanium core had a cross section of 1. 559 4 Transformed section modulus of composite section with 100% composite action referred to the bottom flange of the steel section: S tr≔― I tr y b S tr=67. Concrete-filled circular steel tubes (CFST) are frequently employed as columns of high load- bearing capacity, and their design is well established in many national codes of practice and also in ENV and EN Eurocode 4 by CEN. čSN 42 5550. Sb = non-composite section modulus for the bottom fiber of the beam LRFD PPC Deck Beam Design May 2019 Page 3. Sbc = composite section modulus for extreme bottom fiber of the precast beam = Ic/ybc = 694599. Rigid Pavement Design Chart Segment 1 302-2 January 1999 Ref, Section & Figure 302, 302-1 (step 6) Drainage Coefficient, Cd i__I Example k = 130 pci (Fig. If you could provide feedback, I would appreciate it. The weighted- modulus approach is adopted to find the properties of the laminated composite material. Seff = Effective section modulus of a partially composite beam referred to the extreme tension fiber of the steel beam section (including cover plate, if it exists), in 3. In addition, since the composite material has a different modulus in tension than it does in compression, the "bending" modulus will also be different. load carried by concrete,section in terms of concrete. , plastics are examples of these materials which have unequal moduli of elasticity). Mechanics of MAterials These 56 tutorials cover typical material from a second year mechanics of materials course (aka solid mechanics). Groove Width 8. Composite material is made of 2 or more different materials fabricated together in an object for enhancing. Find the maximum bending stress in each material of the composite beam. 2 mm Thickness 2. 5m Allowable Bending Moment 6kNm Section Modulus 28412mm3 Characteristic Full Section Young’s Modulus* 34GPa Weight/Piece 13kg EZE Slider 0. Plastic Analysis of Beams CEE 201L. COMPOSITE TRENCH SYSTEM 1. 85" 38 ULTIMATE LOAD PER WIRE (lbs) DEFLECTION PER 1000 (in) WEIGHT (lbs) 8. 6] recommends the stress-strain relationships of the materials shall be taken into account. Make sure to. Each shape can have it's own material properties such as weight and modulus of elasticity, and it can either be composite or non-composite to the beam. S s = section modulus of steel beam, in 3 (mm 3 ) S t r = section modulus of transformed composite section, in 3 (mm 3 ) An alternative, shortcut method is permitted by the AISC specification. The section modulus Z = I/ym (where ym is the normal distance from the neutral axis of bending to the outer surface of the beam) measures the surface stress generated by a given bending moment, M :. These tables are to be used only for preliminary beam design. SectProp, Free Download Excel Calculator for calculation of structural beam section properties, i. 6] recommends the stress-strain relationships of the materials shall be taken into account. Introduction: If a bridge deck consists of R. I don't know exactly how G' is determined, but the reason G' is used instead of the typical steel shear modulus is because G' accounts for warping and fastener pattern. Property: Parameter: Value in example a: Unit: Value in template: Unit: Span length, L Sp. University of Michigan, TCAUP Structures II Slide */21 Given: DLslab = 62. if each element of dA in material 2 x n, a new cross section is shown, the N. 120 Load Tables are based on the design of ONE-WAY composite slabs carrying uniformly distubuted loads on a simple span basis. 7 Representation of general beam cross-section with pieces with different values of modulus In the definition of the section properties, have used a y* and z*. Se ction 1: General. Plastic Moments and Section Moduli Basic principle. These are the location of the "modulus-weighted centroid " referred to some. The educational license for the full program is available for our students from Yacht Design School for $195. In that case the whole section is divided in two parts, one in tension and one in compression, each under uniform stress field. Volume 1 Section 3 Chapter 3 BD 16/82 Use of The British Standard ELECTRONIC COPY - NOT FOR USE OUTSIDE THE AGENCY November 1982 PAPER COPIES OF THIS ELECTRONIC DOCUMENT ARE UNCONTROLLED 3/1 3. In polymers, the tensile modulus and compressive modulus can be close or may vary widely. INTRODUCTION A. = Non-composite section modulus for bottom fiber of section S c = Final composite section modulus for bottom fiber of section S i = Section modulus resisting each M i, for bottom fiber of section V cw = Nominal shear strength provided by concrete when diagonal cracking results from excessive principal tensile stress in web w c. The pultrusion process requires little labor and is ideal for mass production of constant cross section profiles. Learn online and earn valuable credentials from top universities like Yale,. 5 psf DLbeam = 135 plf n = 1/9 fsteel = 24 ksi ( Fy = 36 ) fconc = 1. Section modulus depends only on the cross section shape of the beam. The modulus of the cross-section will be then equal to the modulus of concrete. -the section modulus for the steel and concrete: g s s e I Z DD x = +− eg c e I x α = The composite stiffness can be 3–5 times, and the section modulus 1. LECTURE 11. Sx: Section modulus about the X-X axis (strong axis). The modulus of elasticity of this·concrete varied only trom about 2,200,000 to about 4,500. The plastic neutral axis is defined as the axis that splits the cross section in such a way that the compression force from the compression area is equal to the tension force from the tension area. section might also be used for composite construction when the upper and lower flanges are switched. given: steel i-beam bridge, composite design i solution: 3 4 3 4 example #2 given: required: solution: 3 4 3 4 steel i-beam bridge, non-composite design section modulus s, and moment of inertia i section modulus s, and moment of inertia i typical longitudinal section of deck slab with metal form multiply values of s shown in table by:. 4 Rf reduclion faclor for wind forces on exposed HSS R, nominal strength of HSS and conneclions 10 HSS S elastic seclion modulus S