Missile-Target Interaction Analysis

DOE-STD-3014-96

APPENDIX C

W1, V1=

total weight and impact velocity of the aircraft being

considered as a potential missile.

Missile-Target Interaction Analysis

Global response analysis of the target can also be performed by considering the

interaction between the missile and the target instead of using the two-step method

described in Section 6.3.3.2. In this method, the impacting aircraft (missile) is explicitly

modeled with the building structure (target). The aircraft model shall consist of several

mass points interconnected by several nonlinear stiffness springs, and all mass points

shall have an initial velocity equal to the postulated impact velocity. Similarly, the

building model shall consist of several mass points and nonlinear springs, including

massless soil springs representing the foundation flexibility. Depending on the data

available, the aircraft and the building structure can also be represented by detailed finite

elements, instead of lumped masses and equivalent stiffness springs. Also, in either

model, the interface between the aircraft and the target, including the local stiffness and

crushing properties, can be represented in detail. Alternatively, an equivalent nonlinear

interface spring element can be developed from a separate detailed finite element model

and inserted into the overall missile-target interface model.

The response of the above missile-target interface model can be determined using one

of several nonlinear finite element computer codes available in the industry as an initial

velocity problem. The predicted deformation or strain in the various target elements shall

then be compared against the permissible values (see Section 6.3.3.3) to assess if the

target structure can withstand the impact without excessive deformation or collapse.

Target Structure Modeling Guidelines

The type of analytical models used for performing global response evaluations by the

time-history analysis method should depend on the purpose of the analysis and the level

of detail necessary. Generally, an equivalent lumped mass and spring model is

adequate to compute the overall building deformation levels to determine if

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