Hollow material: "hollow"

Input

reference_density
compression_factor
strain_translation
temperature_weighting
temperature_decay
material_data

Notes:

• compression_factor is a general function of type WXC++ Realfunction1d in density.
• strain_translation is a real 3x3 matrix mapping the bulk strain to the strain experienced by the inside surface.
• temperature_weighting and temperature_decay are general functions of type WXC++ Realfunction2d, in density and (bulk) temperature.
• The material data is defined (starting at the top level again) to allow an equation of state etc to be specified.

State

material_state	(for the material type associated with the spall model)
material_state	(ditto, at the inside surface)