Micromechanics
and Laminate Analysis of Textile Fabric Composites
mmTEXlam©
is a graphical user-interfaced program developed to calculate
the material elastic constants and the laminate A, B, and
D matrices of fabric reinforced composite laminates. The program
utilizes the Object Oriented Programming concept of the application
development software Microsoft Visual Basic 5.0 to treat each
task as independent objects. The micromechanics of all 2-D
fiber architectures are described in papers by Naik and 3-
architectures by Branch and Shivakumar.The original Fortran
code TEXCAD, for 2-D fiber architectures was developed by
Rajiv Naik at Analytical Services and Materials Inc. The 3-D
triaxial brand architecture were implemented by Kevin Branch
Kunigal Shivakumar and Rajiv Naik. A basic methodology is
described in this report. Each fabric composite, and its representation
unit cell (RUC) is defined. Within the RUC, the geometrical
description of all yarns are defined along with the interstitial
matrix. Based on the iso-strain assumption, the constitutive
matrix of the composite was developed and from that the elastic
constants were deduced. The laminate analysis was based on
the classical lamination theory. For a defined stacking sequence,
A, B, and D matrices were computed. And then from the A matrix,
the elastic constants were computed. Architectures modeled
are unidirectional, two-dimensional (2-D) biaxial weaves and
braids, 2-D triaxial braids and 3-D four-step circular and
multi-interlock braids.
The
FORTRAN program TEXCAD-3D was fragmented into different objects.
Then a Dynamic Link Library (DLL) of the objects was developed
using Digital Fortran 5.0. The Graphical User Interface (GUI)
was developed in Microsoft VB 5.0 to interact with this DLL.
The GUI invokes the relevant subroutines in the DLL and passes
the input parameters to the FORTRAN program to perform the
calculations. The results can be printed and/or displayed
in tables on a user defined screen. The current GUI version
of the code was developed by Preeti Chella and Kunigal Shivakumar.
The
code usage is self explanatory and each step is guided by
various options and explanations. The user's manual includes
hardware and software requirements, installation and execution
instructions, listing of various fabric architectures modeled,
and a step-by-step screen print of four different examples.
These examples include both micromechanics and laminate analysis.
In the laminate analysis examples, an arbitrary stacking sequence
of 0/+45/-45/90 was chosen
