## 5aSA7. Acoustic signature simulation of a composite armor vehicle using boundary element methods.

### Session: Friday Morning, December 6

### Time: 10:15

**Author: Z. Wu**

**Location: Automated Analysis Corp., 2805 S. Industrial, Ste. 100, Ann Arbor, MI 48104**

**Author: S. T. Raveendra**

**Location: Automated Analysis Corp., 2805 S. Industrial, Ste. 100, Ann Arbor, MI 48104**

**Author: E. Shalis**

**Location: U.S. Army Tank-Automotive Command**

**Abstract:**

Acoustic signatures of ground combat vehicles are very important to their
survivability. In the low-frequency range of 10--200 Hz, the structure-borne
acoustic radiation is mainly due to the track force/moment inputs. Full-vehicle
models were developed to numerically simulate the radiated acoustic signature as
well as the interior noise levels of a new composite combat vehicle at its
design stage. Boundary-element method was used to compute the radiated sound
pressure in the semianechoic condition after mapping normal vibration velocities
(calculated from a finite-element model) onto the vehicle's surfaces [Z. Wu and
E. Shalis, ``Acoustic signature prediction of combat vehicle using finite and
boundary element methods,'' SPIE's 1996 Symposium on Smart Structures and
Materials, 26--29 Feb. 1996, San Diego, CA]. The numerical computation is quite
intensive since a large number of frequency points is required. A matrix
interpolation procedure was used where the actual number of frequency loops are
reduced substantially. It is done by initially computing the solution matrices
at prescribed key frequencies and then computing the matrices at the
intermediate frequencies using a quadratic interpolation. [This work was
partially funded by a U.S. Army SBIR contract granted to Automated Analysis
Corp.]

ASA 132nd meeting - Hawaii, December 1996