Dsload
*Dsload - Distributed surface load
*Dsload, <option>
<surface name>, <load label>, <Load magnitude>
This option defines a distributed surface load acting on the surface
with the name <surface name>
with a defined load magnitude.
-
<option>
Specify how the load should be applied. The load can either be applied:
-
instantaneously (without any temporal delay) using
<option> = instant
-
linearly increasing with step time (0% of the prescribed magnitude are applied at the beginning of the step and 100% at the end of the step time) using
<option> = ramp
-
using a user defined amplitude defined prior to the step definition using
<option> = Amplitude = <amplitude name>
-
using a user defined amplitude defined prior to the step definition using
<option> = Amplitude = <amplitude name>
-
-
<surface name>
Surface name to which the load should be applied.
-
<Load label>
Load label defining the direction of action of the external distributed load. Currently available are:
DSLoad Section Uniform pressure 5.18.3.1 Water weight 5.18.3.2 Springs 5.18.3.3 Compliant base boundary condition 5.18.3.4
Uniform pressure
*Dsload, <option>
<surface name>, P, <Magnitude>
Distributed load acting perpendicular to the surface face.
Water weight
*Dsload, <option>
<surface name>, SWP
Spring
*Dsload, <option>
<surface name>, <spring type>, <magnitude>
<surface name>
by a plurality of spring
elements. Two types of springs are implemented, which can be chosen by setting
<spring type>
to:
-
spring-n
for springs acting perpendicular (in normal direction) to the surface. -
spring-t
for springs acting in tangential direction of the surface
The <magnitude>
corresponds to the normalized
spring stiffness \(k/L\), where \(k\) is the spring stiffness and \(L\) is the
(virtual) length of the spring.
Compliant base boundary condition
*Dsload, <option>
<surface name>, <compliant type>, <dir>, <magnitude>
The compliant base boundary condition is used to impose a seismic signal
at the bottom of the FE model and at the same time damping downwards
propagating waves by applying equivalent viscous forces. The distributed
force acts in global direction Dir
to the
element faces of surface <surface name>
to which
the force is applied. The <Magnitude>
is defined
as \(\rho \cdot c_{p,s}\) of the underlying material, where \(\rho\) is the
density and \(c_{p,s}\) is the wave speed (\(c_s\) for shear waves and \(c_p\)
for compression waves) The subsequent line then reads:
Two types of springs are implemented, which can be chosen by setting
<compliant type>
to:
-
compliant
: This corresponds to the "implicit" implementation, where the current velocity \(v\) is used to calculate the viscous stress -
compliant0
: This corresponds to the "explicit" implementation, where the velocity \(v_0\) from the previous (converged) time step is used to calculate the viscous stress.