GTCOMPROP (Georgia Tech COMposite Material Member PROPerties calculator) Structural Engineering Software for the Analysis of Space Frame Structure Composed of Fiber Reinforced Composite Materials Presented by Gwang-seok Na Advisors : Dr. Leroy Z. Emkin & Dr. Abdul Hamid Zureick Civil & Environmental Engineering Georgia Institute of Technology June 23, 2006 Good afternoon everyone. My name is Gwangseok Na. I’m in a PhD program at Georgia-Tech and working as a RA. Today I hope to present a new engineering software named GTCOMPROP. This name represent “Georgia Tech Composite material member properties calculator” This implemented software is a structural engineering software for analysis of space frame structure of fiber reinforced composite materials

Overview Introduction Theories on Calculation of Anisotropic Space Frame Member Stiffness Matrix Software Implementation Analysis Example At first, I start introduction including motivation, objectives, and some basic knowledge on FRP composite member And I’ll present the theories on calculations of Anisotropic space frame member stiffness matrix I’ll show main features of the implemented software And nest, I’ll show the sample analysis case using the developed software

Motivation FRP composite materials have attractive characteristics for civil engineering applications. High Strength to Weight Ratio Corrosion Resistance Various Section Profiles ( Courtesy of Creative Pultrusions Inc. ) Conventional structural analysis techniques possess limitations in their ability to accurately analyze space frame structure composed anisotropic members. A new pioneering technology has been developed and used in aerospace industry, but not civil industry because of its complexity. As you know well, Fiber reinforced materials have a lot of attractive characteristics for civil engineering application Like high strength ratio, corrosion resistance …… [BULLET] … The reason is because that conventional analysis techniques calculate the stiffness characteristics of member based on the cross section geometry alone and assume the material is isotropic and in addition to homogeneous However a new pioneering technology has been developed in aerospace engineering area in order to calculate member stiffness of highly anisotropic member But this technique has not been used in civil engineering because of the variety of complexities in using this techniques.

Objective Develop analysis methodology, which can be used for civil engineering frame structure, based on Variational Asymptotic Beam Sectional Analysis Method. Implement user-friendly engineering software that can fully utilize the developed analysis methodology. So the objectives of this research is : Developing analysis methodology that can be proper a for civil engineering application Implement user-friendly engineering software that can fully utilize the developed analysis methodology Next, I’ll talk about what is FRP composite materials

FRP Composite Materials – An Analogy Reinforced Concrete (RC) Materials Fiber Reinforced Polymeric (FRP) Composite materials Then I’ll talk about what is composite materials here. To help understanding the concept of FRP composite materials I compared the FRP composite materials case with Reinforced Concrete (RC) Materials RC is also a simple composite materials composed with concrete and reinforcing bars If we see concrete in micro-scale level Concrete is also thought as composite of cement and aggregiate Just like this RC, composite materials is composed with several different materials having different materials properties. FRP composite materials is compsoed of matrix and reinforcing fibers Just like concrete, matrix is also composed with resin and filler Unlike RC case, various reinforcing arrangement are possible In both cases, complex mathmatical models are required to get the effective material properties of these composite This is called composite layers This will be stacked to form the required thickness of flange of web of the member cross cross section Concrete Reinforcing Bars Matrix Reinforcing Fibers Cement Aggregate, Sand and Additives Resin Filler and Additives

FRP Composite Materials Reinforcement Systems (Fibers) [ Analogous to Reinforcing Bars in RC] Provide main strength and stiffness in a fiber direction Materials : Glass / Carbon (graphite) / Aramid (Kevler®) / Boron Several fiber arrangement configuration is possible Matrix [Analogous to Concrete in RC] Transfer stress, protect fiber Composed of resins and fillers Resin [Analogous to Cement in RC] : Polyester / Vinylester / Epoxy Filler [Analogous to Aggregate in RC] : Calcium Carbonate, Kaolin clay Additives : Colorant Etc. Reinforcing systems provide main stregth and stiffness in fiber direction Glass, Carboon, Aramid are categorized into this Main role of matrix is transfering stress and protecting fiber Polyester, Vinylester and epoxy are popular resin material

FRP Composite Materials Roving-reinforced layers 1 directional oriented fibers Micromechanics models : Chamis model (1984) Halpin-Tsai(1968) Continuous Strand Mat (CSM) - reinforced layers Randomly oriented fibers Micromechanics model : Tsai-Pagano model (1968) Christensen model (1972) ( Courtesy of Owens Corning Inc. ) The composite layers that all fiber are arranged in uni-directionally is called “Roving reinforced Layer” There are variety of micro mechanics mathematical formulations that has been developed to get the elastic engineering properties of this composite layer. Among them, the Chamis & Halpin-Tsai models are chosed in this research The composite layers that reinforcing fibers are arranged randomly manner is called “Continuous strand mat reinforced Layer” ( Courtesy of Owens Corning Inc. )

FRP Composite Materials A components (e.g., web or flange) of cross-section can be made with multiple-layers CSM Roving CSM This is a example of Box-cross section where the components of cross section is consist of multiple layers that was shown in previous slides, “Roving reinforced layer” and “CSM reinforced layer” These composite layers can be used to form the thickness of web or flange of cross-sectioin Other combination of layers can be used by engineer and manufacturer. Roving CSM Roving CSM

Overview Introduction Theories on Calculation of Anisotropic Space Frame Member Stiffness Matrix Software Implementation Analysis Example

Effective Material properties – Composite Layers Roving–reinforced layers 1 directional oriented fibers Micromechanics model : Chamis model (1984) Halpin-Tsai(1968) Continuous Strand Mat (CSM) –reinforced layers Randomly oriented fibers Tsai-Pagano model (1968) Christensen model (1972) This part is a quick review of mathmatical formulations for Roving layers and CSM layers

Effective Material properties - Composite Layers Chamis model (1984) for Roving-reinforced layers E11 : Effective longitudinal Modulus E22 , E33 : Effective Transverse Moduli in axes 2 , 3 G12 , G13 , G23 : Effective Shear Moduli in plane 1-2,1-3, 2-3 ν12, ν13, ν23 : Effective Poisson’s ratio in plane 1-2, 1-3, 2-3 vf : Volume fraction of Fiber vm : Volume fraction of Matrix I’m not now presenting how these equations are folmulated This is a result of mathmatical formulations of Chamis model The 9 effective elastic engineering properties, 3 modulus, 3 shear modulus, 3 poisson’s ratios, can be calculated based on 3 elastic engineering properties of both fiber and matrix The material properties of Fiber and Matrix are well known 1 2 3 Em , Gm , νm: Elastic Properties of Matrix Ef , Gf , νf: Elastic Properties of Fiber

Effective Material properties - Composite Layers Roving–reinforced layers 1 directional oriented fibers Micromechanics models : Chamis model (1984) Halpin-Tsai(1968) Continuous Strand Mat (CSM) –reinforced layers Randomly oriented fibers Micromechanics model : Tsai-Pagano model (1968) Christensen model (1972)

Effective Material properties - Composite Layers Tsai-Pagano model (1968) for CSM-reinforced layers , , , , E : Effective Young’s modulus G : Effective Shear modulus ν : Effective Poisson’s ratio Em : Matrix modulus Ef : Fiber modulus The effective material properties of CSM layer can be calculated by developing equivalent isotropic material properties Because fiber are orient in randomly oriented and have no particular direction These equivalent isotropic material properties are based on the some fictious material properties E11* and E22* are fictious modulus based on chamis model and Halpin-Tsai model E11* is same in both case But E22* have two different version based on micro mechnics models, and these can be showed in previous slides vf : Volume fraction of Fiber vm : Volume fraction of Matrix E *11 , E *22 : Fictitious Longitudinal modulus and Transverse modulus by Chamis model or Halpin-Tsai model

The thickness of a flange or web Effective Material properties – Components of Cross-Sections Lamination Theory - Homogenization 3 1 2 Layers n s x xt Previous slides presented how to calculate Roving layer properties and CSM layer properties. The problem is that the components of cross-section is consist of multiple layers And each layer can be either roving layer and continuous strand mat layer The properties of each layer can be different Now, the special technique called Lamination theory can be used to get effective material properties of components of cross-section web or flange This is kind of homogenization technique to derive the equivalent material properties. The thickness of a flange or web

Effective Material properties – Components of Cross-Sections Sun & Li 3D Lamination Method (1988) Effective Elastic Properties There are several Laminations theories are available These are final mathematical formulation of Sun’ Li’s model As we can see 9 elastic engineering properties can be calculated for each component of cross-section Through this mathematical procedure engineer can

Anisotropic Member Stiffness – Sectional Analysis Variational Asymptotic Beam Sectional Analysis (VABS) Method (Developed by Dr. Hodges of Aerospace Eng. at Georgia Tech., 1994 under Gov. Fund.) 2D SECTIONAL ANALYSIS 3D FINITE ELEMENTS MODEL X2 X3 X1 SECTIONAL STIFFNESS Ok I’ll talk about the most important theories in this program from here. The most exact way of modeling the anisotropic member is known as modeling member with 3D finite elements But this method is extremely difficult to model and time consuming. That not proper for civil engineering However VABS method broke down original 3D problem into two parts The first one is 2D problem that generate so called sectional stiffness The effective material properties that was calculated though 3D Lamination theories now can be used for 3D element of cross section The second part is calculating the stiffness 1Dimensional member stiffness from 2D sectional stiffness through some mathematical approach X2 X3 X1 Start-end End-end MEMBER STIFFNESS 1D SPACE FRAME STRUCTURAL MEMBER

Overview Introduction Theories on Calculation of Anisotropic Space Frame Member Stiffness Matrix Software Implementation Analysis Example

Software Implementation – GTCOMPROP Main window The every mathematical procedures so far was implemented and integrated into this software

Software Implementation – Fiber Material Properties Database Then I’ll explain about some important dialog windows in this program first This dialog window is used to use to define the material properties of Fiber from a manufacturer FIBER FIBER

Software Implementation – Matrix Material Properties Database This dialog window is used to use to define the matrix properties of Fiber from a manufacturer MATRIX MATRIX

Software Implementation – Effective Engineering Properties of Single Layer Calculation This dialog is used to create composite material properties of various composite layers based on the previously introduced several micromechnics models Here we can decide materials for Fiber and Matrix And We can decide some required parameters And We can select micromechanics model The generated result can be stored for future use

Software Implementation – Effective Engineering Properties Calculation of Multi-Layered Components of Cross-Section This dialog window is used to calculate the effective elastic engineering properties of components of cross section that is consist of multiple layers We can construct specific layer sequence with previously calculated composite layers result This is based on the previously presented 3D Lamination theory The generate result also can be store for future use. LAYER #1 (CSM) LAYER #2 (ROVING) :

Software Implementation – Section Shapes (1/2)  Sections for Isotropic Materials RECTANGLE CIRCULAR AASHTO BEAMS  Sections for Anisotropic or Isotropic Materials (1/2) I SHAPE T SHAPE CHANNEL L SHAPE DOUBLE ANGLE

Software Implementation – Section Shapes (2/2)  Sections for Anisotropic or Isotropic Materials (2/2) N-SIDES HOLLOW TUBE DOUBLE WEB BOX BOX TUBE CIRCULAR TUBE TRIANGULAR CELL BOX RECTANGULAR CELL BOX BRIDGE DECK

Software Implementation – Section Generation

Software Implementation – Member Stiffness Calculations – Anisotropic Materials

Software Implementation – Section Properties Calculations – Isotropic Materials Centroidal Location Principal Axis Orientation Cross Sectional Area Principal Axis Shear Areas Principal Axis Moments of Inertia Torsion Constant Warping Constant Shear Center Location Member Natural Stiffness Matrix

Overview Introduction Theories on Calculation of Anisotropic Space Frame Member Stiffness Matrix Software Implementation Analysis Example

Analysis Example – Geometry of Sample Structure At first, I start introduction including motivation, objectives, and some basic knowledge on pultruded FRP composite And If time’s permit, I’ll show a program demonstration.

Analysis Example – Wind-Loadings on Sample Structure At first, I start introduction including motivation, objectives, and some basic knowledge on pultruded FRP composite And If time’s permit, I’ll show a program demonstration.

Analysis Example – Anisotropic Material Member Section Profiles COLUMN B = 20”, D = 20”, tw=tf=1.0” At first, I start introduction including motivation, objectives, and some basic knowledge on pultruded FRP composite And If time’s permit, I’ll show a program demonstration. GIRDER B = 12”, D = 30”, tw=tf=1.0” STRUCTUR-1

Analysis Example – Anisotropic Material Member Section Profiles At first, I start introduction including motivation, objectives, and some basic knowledge on pultruded FRP composite And If time’s permit, I’ll show a program demonstration. BRACINGS B = 6”, D = 6”, tw=tf=1.0” STRUCTUR-2

Analysis Example – Effective Engineering Material Properties  Nominal Elastic Properties of Composite Constituents E (ksi) G (ksi) v E-glass Fiber 10,500 4,375 0.2 Polyester Matrix 573 210 0.36  Volume Fractions vfiber = 35.3 % vmatrix = 63.0 % vvoid = 1.7 % CSM ( 10 oz/yd2 ) Roving ( 37.2 oz/yd2 ) 2-CSM (10 oz/yd2 ) Ex = 2,822 ksi Es = 1,896 ksi Gxs = 640 ksi vxs = 0.39 Roving ( 37.2 oz/yd2 ) 2-CSM ( 10oz/yd2 ) Roving ( 37.2 oz/yd2 ) CSM ( 10oz/yd2 )

Analysis Example – Effective Engineering Material Properties

Analysis Example – Effective Engineering Material Properties

Analysis Example – Section Generation

Analysis Example – Section Generation

Analysis Example – Section Generation

Analysis Example – Anisotropic Material Member Stiffness Results Input : $ ----------------------------------- $ Space frame member KBB 6x6 matrix $ Shape: W-SECTION $ Description : GIRDER D=30 B=12 TF=1.0 TW=1.0 LENGTH = 11 FT $ Units: INCHES LBS RADIANS $ Member length: 132.000000 in UNIT INCHES LBS RADIANS MEMBER PROPERTIES 40 41 42 43 44 45 - 46 47 48 49 50 51 - 52 53 93 94 95 96 - STIFFNESS MATRIX COLUMN 1 2 3 4 5 6 ROW 1 6.587e+005 0.000e+000 6.541e-014 5.204e-017 -1.820e+002 4.114e+003 ROW 2 0.000e+000 3.207e+004 3.095e-002 -1.336e+001 2.043e+000 -2.116e+006 ROW 3 6.585e-014 3.095e-002 2.776e+003 -6.833e-001 1.832e+005 -2.043e+000 ROW 4 5.031e-017 -1.336e+001 -6.833e-001 4.442e+004 -4.510e+001 8.819e+002 ROW 5 -1.820e+002 2.043e+000 1.832e+005 -4.510e+001 1.624e+007 -2.632e+002 ROW 6 4.114e+003 -2.116e+006 -2.043e+000 8.819e+002 -2.632e+002 2.347e+008 At first, I start introduction including motivation, objectives, and some basic knowledge on pultruded FRP composite And If time’s permit, I’ll show a program demonstration.

Analysis Example – Analysis Results ( No–Bracings ) At first, I start introduction including motivation, objectives, and some basic knowledge on pultruded FRP composite And If time’s permit, I’ll show a program demonstration.

Analysis Example – Analysis Results ( Bracings ) At first, I start introduction including motivation, objectives, and some basic knowledge on pultruded FRP composite And If time’s permit, I’ll show a program demonstration.

Summary of Current State of Research Completed the implementation of a highly rigorous procedure for the member stiffness matrix for Anisotropic composite structural members Completed incorporation of advanced anisotropic member stiffness calculation features with GT- STRUDL.

Thank you Questions ?