CAE Fidesys 9.0 Documentation

Radiation Swelling

A linear swelling model, a new load type "Fluence" and a new material property "Linear Swelling Coefficient" have been added to solve radiation swelling problems.

Swell is the expansion of a material (volumetric expansion) caused by neutron bombardment or other effects (such as moisture).

In general, the rate of deformation during swelling depends on factors such as time, temperature, fluence (flow × time) and stress.

,

where t – time, T – temperature, Ф_t – fluence, σ – stress.

In CAE Fidesys 7.0, a linear swelling model was implemented in which the swelling deformations depend only on the fluence value and the linear swelling coefficient:

.

Swell strain is modeled using additive strain decomposition, expressed as:

,

where ξ – is the total strain, ξ^el – elastic deformation, ξ^pl – plasticity strain, ξ^cr – creep strain, ξ^SW – swell strain.

Swell can be combined with other material models with deformations such as plasticity and creep.