LAP

LAP - Laminate Analysis Program

What does LAP do?

The Laminate Analysis Program can be used to analyse any type of composite laminate subjected to in-plane loads and moments. The flat laminate has no fixed size apart from its thickness, so that the analysis can be applied to any composite component, at a location where loadings or deformations are known. Typically, the software is used in preliminary design for tailoring a stacking sequence, then analysing the composite component with other methods such as finite elements, and finally optimising the design by inspecting the laminate behaviour layer by layer.

LAP consists of four modules. The Basic module includes the linear analysis functionality and constitutes the minimum configuration. The other three modules (Non-Linear, Design, Additional Failure criteria) are optional.

Laminate Analysis Program

Enhancements in version 4

Modular design delivers flexibility and best value for money.
The Design module offers a unique method for laminate design, where a collection of user-defined design criteria are transformed into candidate stacking sequences.
The BFS failure criterion computes longitudinal compressive strength for notched or unnotched laminates.
There is now the capability of applying a user-defined failure criterion to the linear or non-linear solutions.
There are additional data export interfaces.
There are several enhancements to the user interface

Key Benefits

The simplicity of the analysis ensures universal applicability, since it is not limited by structural shape. Typically, the software is used in preliminary design for tailoring a stacking sequence, then analysing the composite component with other methods such as finite elements, and finally optimising the design by inspecting the laminate behaviour layer by layer.
The software maintains its emphasis on ease of use and fast, efficient, robust solvers. The graphical interface for data manipulation and for inspection of results guarantees instant familiarity and in-depth understanding of composite laminate behaviour.
The program's powerful features make it an ideal tool for the demanding expert, yet a newcomer to composites can complete simple tasks within minutes. It is characteristic that the software is used by industry in aerospace, ship building, car racing, etc., as well as in academic and professional teaching courses.

Basic module

The Basic module provides the linear analysis functionality: Curing, Hygroscopic, Thermal and Mechanical loadings are supported. Their effects can be viewed in isolation instantly. Mechanical loading can be defined by Load/Moment and/or Strain/Curvature components, in an optional sequence of application. The effects of manufacturing deviations from the nominal fibre volume fraction can be uniquely included. The main results include effective stiffness constants for the laminate, effective hygroscopic and thermal coefficients, solution matrices and vectors. The expected in-plane laminate strength is computed, both initial and ultimate (iterative algorithm). Layer stress and strain can be examined in the global or fibre axis systems. The built-in failure criteria are Tsai-Wu, Tsai-Hill, Hoffman, maximum stress, and maximum strain. The laminate displaced shape can be seen in 3D, a useful tool in visualising the laminate behaviour under load. Polar plots of effective laminate stiffness and hygrothermal coefficients conveniently demonstrate off-axis laminate behaviour.

Stress analysis on laminated composites Failure of laminated composites

Non-Linear module

The optional Non-Linear module extends the analysis functionality to include the effects of non-linear material stiffness: Mechanical stiffness properties may be defined as piecewise functions of local stress or strain. The ability to set stiffness reduction factors upon layer failure is included. An accurate picture of non-linear laminate stiffness response is given up to and beyond layer failure. This feature is very powerful, since it offers in-depth understanding of what can happen to a composite component under high stress, thus increasing confidence in the design. Related effects, such as the shift in neutral axis under bending load, can also be monitored. Results include X-Y plots of virtually any combination of two result entities.

Non linear analysis of laminated composites

Design module

The optional Design module introduces a new dimension to LAP, in two variants: The Laminate Design procedure consists of specifying a set of mechanical loadings, each with stiffness and strength constraints which must be satisfied by an optimum symmetric laminate to be designed. The materials and fibre angles to be considered by the software, as well as a number of other options, are specified by the user during the design process. LAP carries out a thorough investigation of the candidate stacking sequences and presents a finite set to the user, for further selection or optimisation. The method is unique in its conception and implementation. With Batch Solution, a number of laminates are examined to confirm that they indeed satisfy the stiffness and strength requirements set by the user. Typically, this is used to confirm compliance after changes have been introduced to the laminates suggested by the software.

Design of laminated composites

Additional Failure Criteria module

This optional module extends the LAP analysis functionality as follows:

The BFS failure criterion (Budiansky-Fleck-Soutis) is used to calculate the unnotched as well as the notched longitudinal compressive strength for a laminate. The notch geometry can be one of: centre notch, edge notch, open hole, countersunk hole, or filled hole.
Through a user-supplied function, a custom failure criterion can be defined for use with linear or non-linear strength analysis.

Additional Failure Criteria for laminated composites

User Interface features

The graphical user interface includes all the features expected of a professional, state-of-the-art, technical software application.
Any type of results can be displayed simultaneously on any number of independent windows.
Interfaces for data quantities can be used to import or export information and communicate with other applications. Interfaces for results can be used to export results to files or to the Windows clipboard for instant transfer to spreadsheets, word processors, or custom application software.
Generic reports can be defined to obtain professional quality printed output of text and graphics efficiently. The contents of any window can be printed instantly in isolation.
Drag-and-drop copy operations between LAP files can be used for any database object, such as a material, lay-up, etc.
Multi-level Undo and Redo functions, as well as a timed Auto-Save feature ensure data safety.
A choice of working units is available at any stage, for both input and output.
Quick interactive solutions and results updates save you time.
Application-wide as well as file-specific user preferences offer a consistent working environment.
The desktop layout of the various working windows can be saved for easy return to a particular problem, even when working with computer screens set at different resolutions.
A convenient custom screen font is used to display standard engineering symbols.
Groups of material properties, stacking sequences, loading conditions and supporting information are saved in database files and restored as needed.
There are no limits to the database size.
Multiple database files can be open simultaneously.
The supplied printed documentation explains how to use the software, offers useful tips and covers all theoretical background.

Help is available in the familiar Windows hypertext format.

System Requirements

PC with Intel Pentium or compatible processor, Windows 95/98/NT/2000/XP, 64 Mb RAM, 10Mb hard disk space, high resolution display recommended, floppy disk and CD-ROM drive for installation. PC with Intel Pentium or compatible processor, Windows 95/98/NT/2000/XP, 64 Mb RAM, 10Mb hard disk space, high resolution display recommended, floppy disk and CD-ROM drive for installation.