I have been working on a Nastran op4 file reader in Julia for a while in my spare time. The idea is to use it in my research on model-order reduction that I'm implementing in Julia.
A version with support for OP4 and SOL103, SOL111/108 punch file reading can be found here: NastranResults.jl. HDF5 ability will be added later.
Installed using Pkg as
julia> ]
pkg> add https://github.com/mgcth/NastranResults.jl