Page 23 - Using ANSYS for Finite Element Analysis A Tutorial for Engineers

10 • Using ansys for finite element analysis
not induce significant inertia and damping effects. Steady loading and
response conditions are assumed; that is, the loads and the structure’s
response are assumed to vary slowly with respect to time. The kinds of
loading that can be applied in a static analysis include:

• Externally applied forces and pressures
• Steady-state inertial forces (such as gravity or rotational velocity)
• Imposed (nonzero) displacements
• Temperatures (for thermal strain)
• Fluences (for nuclear swelling)

1.1.6.2 transient dynamic analysis (linear and nonlinear)

Transient dynamic analysis (sometimes called time history analysis) is
a technique used to determine the dynamic response of a structure under
the action of any general time-dependent loads. You can use this type of
analysis to determine the time-varying displacements, strains, stresses,
and forces in a structure, as it responds to any combination of static, tran-
sient, and harmonic loads. The time scale of the loading is such that the
inertia or damping effects are considered to be important. If the inertia
and damping effects are not important, you might be able to use a static
analysis instead.

1.1.6.3 Modal analysis

You use modal analysis to determine the vibration characteristics (natural
frequencies and mode shapes) of a structure or a machine component
while it is being designed. It also can be a starting point for another,
more detailed, dynamic analysis, such as a transient dynamic analysis,
a harmonic response analysis, or a spectrum analysis.

1.1.6.4 harmonic analysis

Any sustained cyclic load will produce a sustained cyclic response (a
harmonic response) in a structural system. Harmonic response analysis
gives you the ability to predict the sustained dynamic behavior of your
structures, thus enabling you to verify whether or not your designs will
successfully overcome resonance, fatigue, and other harmful effects of
forced vibrations.