Accession Number:



Representing a Pressure Load Boundary Condition as a Resultant Acceleration Boundary Condition in Finite Element Modeling

Descriptive Note:

[Technical Report, Final Report]

Corporate Author:


Personal Author(s):

Report Date:


Pagination or Media Count:



A comparative study was performed to understand how the representation of the driving load affects the predicted system response. Using a simple axisymmetric model of a canister partially filled with an epoxy subjected to a drop based impact event, the system behavior when subjected to a transient pressure-based load at the impacted surface was compared to the behavior when the entire outer surface of the canister was prescribed the bulk acceleration of the system calculated from the pressure used in the other model and the total system mass. The contact force and local accelerations within the canister as a result of the movement of the epoxy moved within the canister were compared between the two models. The maximum contact force and time of initial contact as the epoxy separated from the canister and moved toward an initially unloaded surface within the canister differed by approximately 15 between the models, within the variation that typically can be expected in experimental studies. However, the differing oscillatory responses after this initial impact indicate that the acceleration-based model may artificially stiffen the system when compared to the pressure-based model. Therefore, depending on the intent of the simulation, one representation of the environmental loads on the system may be preferable to the other. This study provides insight into the benefits and limitations of these two common methods of driving dynamic system behavior in a finite element model and can help aid in the selection of the means that may be suitable for a particular problem of interest.


Subject Categories:

  • Numerical Mathematics
  • Mechanics

Distribution Statement:

[A, Approved For Public Release]