2024

This manual provides details on the features, functionality, and simulation methods available in Altair Radioss.

In this section, available explicit features for different explicit analyses are presented.

An explicit is solved by calculating results in small time increments or time steps. The size of the time step depends on many factors but is automatically calculated by Radioss.

The time step can often be increased using some of these time step control methods.

View new features for Radioss 2024.

Radioss^{®} is a leading explicit finite element solver for crash and impact simulation.

Discover Radioss functionality with interactive tutorials.

The Radioss solver can be executed using different methods described here.

The default time step calculation used by Radioss is the element time step.

The nodal time step calculates the time step based on the nodal mass and nodal stiffness in the model.

The global time step (GTS) method can be used to calculate the time step of a model based on the natural frequency of the model.

The contact interface time step is calculated in two different ways. First, based on stiffness and second, based on the velocity of the secondary nodes.

The time step of the initial model is output to the Starter output file. Whereas the time step of a running model can be output to the animation files.

AMS (Advanced Mass Scaling) saves significant computation time by increasing the time step of the model for an explicit computation. This is similar to traditional mass scaling, except that the added mass does not increase the translational kinetic energy of the system.

The theoretical stable time step for both elements and nodes is an approximation and may change during the following time increment.

Every time step control method has advantages and limitations.

Different material tests could result in different material mechanic character.

Composite materials consist of two or more materials combined each other. Most composites consist of two materials, binder (matrix) and reinforcement. Reinforcements come in three forms, particulate, discontinuous fiber, and continuous fiber.

In Radioss, a kinematic condition is a nodal constraint applied to a set of nodes.

Several interfaces are available in Radioss, this section deals with contact interfaces only. Each interface is distinguished with a type number.

Airbags are modeled as monitored volumes /MONVOL in several different ways.

In this section, fluid and fluid-structure simulation is presented.

The Smooth Particle Hydrodynamics method formulation is used to solve the equations of mechanics, when particles are free from a meshing grid.

The objective of the Multi-Domain technique (also referred to as RAD2RAD) is to optimize the computing performances of large scale Radioss models.

Optimization in Radioss was introduced in version 13.0. It is implemented by invoking the optimization capabilities of OptiStruct and simultaneously using the Radioss solver for analysis.

This section is comprised of error messages in ascending numerical order.

This section is comprised of warning messages in ascending numerical order.

This manual provides a detailed list of all the input keywords and options available in Radioss.

This manual presents examples solved using Radioss with regard to common problem types.

This manual presents solved verification models.

This section provides quick responses to typical and frequently asked questions regarding Radioss.

This manual provides detailed information about the theory used in the Altair Radioss Solver.

This manual describes the interface between Altair Radioss and user subroutines.

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