Four classes specific to Classical Laminate Analysis calculations have been defined in the FeResPost module:
The “ClaDb” class allows the definition of composite databases used to store composite materials, laminates, and loadings. This class is presented in Chapter II.2.
The “ClaMat” class allows the definition and manipulation of materials. This class is presented in Chapter II.3.
The “ClaLam” class allows the definition and manipulation of laminates. This class is presented in Chapter II.4.
The “ClaLoad” class allows the definition and manipulation of loadings applied to laminates. This class is presented in Chapter II.5.
Throughout the composite manual, the concept of identifier is frequently used. An identifier can be:
An integer,
A string,
Or an array of two elements (an integer and a string).
This concept was introduced to provide a general way to identify and access materials, laminates, or loads stored in a ClaDb object. The methods used to access these data must be compatible with several software packages (ESAComp, finite element solvers, etc.). Since entities manipulated by these packages are sometimes identified by integers, sometimes by strings, and sometimes by both an integer and a string, this flexible identification scheme had to be developed. For example, if a ClaLam object has been stored in a ClaDb, it can be retrieved with:
...
db.insertLaminate(lam1)
...
lam2=db.getLaminateCopy(5)
...
lam2=db.getLaminateCopy("panel1")
...
lam2=db.getLaminateCopy([5,"panel1"])
...
Note, however, that the identifier used to retrieve lam2 must match exactly the identifier of lam1. For example, if lam1 has the [5,"panel1"] identifier, only the third getLaminateCopy call will work.
This leads to a final remark about interfaces with other software. The composite classes are designed to be used together with the rest of FeResPost. Among other things, this makes it possible to:
Produce layered results automatically, using the laminate definitions and, for example, results corresponding to in-plane forces and bending moments in 2D elements,
Calculate the corresponding failure indices, strength ratios, and reserve factors, all of which are instances of the FeResPost::Result class.
…
The composite capabilities are based on Classical Laminate Analysis as widely presented in the literature. The implementation follows [Gay97]. For the in-plane and flexural parts of the laminate response, the approximations used in the derivation of the equations are consistent with those found throughout the literature. However, fewer references are available regarding the out-of-plane shear behavior of laminates. In [Gay97], this aspect of laminate analysis is presented under several simplifying assumptions. For instance, Gay assumes mirror symmetry of the laminate, which is not a property shared by all laminates. Therefore, the out-of-plane shear responses calculated by the composite classes should be used with care.
More information about the conventions used in FeResPost composite calculations is given in Chapter II.1.