Dynamics & Vibration Testing
Contact DTB with your product testing requirements. Our A2LA accredited lab can satisfy simple and complex test requirements.
This page lists dynamic tests we perform, any of which may be combined with a complete range of environmental simulations for reliable product testing – especially to methods of MIL-STD-810. See our environmental testing capabilities.
Dynamic and Vibration Testing
Vibration testing can help ensure that your new design will survive its intended environment. Submitting your product for vibration testing or vibration analysis pays for itself by reducing field return costs through improved product reliability.
Our vibration testing facilities are comprised of 15 electrodynamic and hydraulic multi-axis shakers to provide over 24,400 N (55,000 lbf) in practically any type of vibration testing event – sine, random, sine on random, and random on random testing.
All vibrations and impulses are not alike. Per your product’s requirements, Dayton T. Brown can either reference industry standards or design a unique vibration or shock testing profile, using a wide variety of methodologies and test equipment in our extensive facilities.
We can combine several test methods to simulate your anticipated conditions – mechanical vibration, pneumatic vibration testing, or hydraulic induced vibration testing combined with various atmospheric/climatic conditions.
Choose which Unholtz-Dickie shaker is appropriate for your vibration job: T5500-3, T4000, T2000, or one of our T1000 vibration systems. (pictured below)
The T5500 Test System is the most advanced in the world with a 3 inch displacement capability and the optional head expander in vertical operation. DTB is the ONLY independent test lab with this capability. The T5500 has a force rating of 55,000 pounds for sine and random vibration and 100,000 pounds for shock.
The T5500, T2000 and the T1000 have an integrated slip table for ease of set up and added support. All five shakers, the T5500, T4000, T2000, and the two T1000 systems can be used for combined environment testing of temperature + vibration and temperature/humidity + vibration. The self-aligning 60″ by 60″ head expander for larger test items can be used on either the T5500 or the T4000.
With the T-5500, DTB remains the leader with the ability to meet the ever-changing demands and challenges of today’s commercial, aerospace, and military testing world. We are able to handle even the most extreme level of vibration requirements and we are capable of testing all of this with a 3 inch displacement.
Since our system has an integrated slip table assembly, we will eliminate wasted set up time in the horizontal axes, making testing time more cost efficient for our customers!
Dayton T. Brown has six facilities which combine temperature/humidity chambers with electro-dynamic vibration testing facilities. The chambers have rapid rates of temperature change and the vibration testing facilities can handle 18,000 force-pound loads with frequencies up to 2000 Hz. In a single vibration test, we’ll mix it any way you like, and include all the advanced data acquisition you want: mechanical vibration, electrical stress, pneumatic, hydraulic combined with vibration testing, temperature, humidity or altitude.
Acceleration Testing Services – We have a dynamic testing facility that includes underground and above ground centrifuges that you can use for acceleration testing. Our 12 M (40 ft) centrifuge can impose a maximum of 300 g’s of acceleration on test items and can carry a max payload of 680kg (1500 lbs). Centrifuge tests are used to meet acceleration requirements of MIL-STD-810 method 513.5, MIL-STD-202 method 212A, MIL-STD-750 method 2006 and other specifications. We have adjustable fixtures that allow the test item to be tilted and rotated in order to match combined load vector test requirements. Data acquisition on test items during the test or monitoring of the test unit operation during the test is also available.
Our electromagnetic shakers, electro-hydraulic actuators or eccentric mass vibration test generators are used in forced vibration testing, and can be applied in steady state, transient or random vibration to produce the required motions or responses for our vibration analysis.
Acoustic / Noise Testing
Seismic - Shipboard & Earthquake Testing
Extended Seismic Testing Capabilities In addition to the initial association with earthquakes, seismic testing is regularly utilized to determine the effects of movement or vibrations from railway, airports, power plants, machinery and other sources of vibratory activity. Our vertical and horizontal seismic testing facilities, manufactured by the Team Corporation, offer low frequency, high displacement seismic vibration capabilities to meet the Bellcore GR-63 Zone 4 seismic testing requirements. The seismic testing systems are also used for all types of Mil-Std vibration and shock testing. An example is the shipboard seismic testing requirement of Mil-Std-167-1.
Our full-service seismic vibration facility is capable of:
- Replicating a Zone 4 seismic event
- Testing payloads greater than 6,000 lbs. with a center of gravity 5 feet above the table
- Dynamic force ratings to 32,000 lbs. in horizontal; 32,000 lbs. in vertical.
- Tests needing a Table size of 6 feet x 8 feet horizontal; 6 feet by 6 feet vertical.
- Tests needing a Full rated performance to 100 Hz.
- A dynamic displacement 10.5 inches, overall displacement 12 inches.
- A maximum velocity of over 40 inches/second.
Shock Testing - Hammer, Pyrotechnic, DDAM
Shock Testing Services
Our shock testing engineers will condition, plot and help you analyze up to 128 channels of real time data – Shock Response Spectrum (SRS), Fast Fourier Transform (FFT) or modal analysis.
Classical Shock Testing is accomplished using many facilities here at DTB. The typical shock testing event can be performed on our Unholtz-Dickie T-4000 and T-1000 vibration testing systems. These Vibration Testing systems coupled with 360KVA of amplifier power permits the system to achieve shock testing levels of over 100Gs. Also, ask about our new T5500 with head expander, integrated slip table and 3 inch displacement.
For tests that required higher levels or longer duration, DTB has additional mechanical shock testing machines. Using these shock testing facilities, levels of 3000 G and 4 mSec, half sine shocks have been developed for our customers. Longer duration shock testing pulses have also been obtained. These long duration pulses range from over 1 second in duration using our Catapult facility to 100 mSec.
Modern engineering techniques often call for unusual and difficult shock testing and vibration testing requirements. However, DTB’s staff of highly skilled engineers and technicians have years of experience in setting up and running these types of dynamic tests.
About Hammer Shock Testing & MIL-S-901
|Stidd Medium Weight Hammer Shock to MIL-S-901DTB has Medium weight hammer shock as well as light weight hammer shock testing facilities, which are both Navy Certified and approved. These shock testing facilities are totally capable of performing Mil-S-901 test requirements.|
About Pyrotechnic Shock Test
Our Shock Testing group has developed and refined the ringing plate method of producing repeatable Shock Response Spectrums (SRS) to over 32,000 Gs. Our pyrotechnic shock testing facilities and mechanical shock testing machines (small and medium weight) can be tailored to produce the required shock pulse.
These shock testing facilities can produce this high level as well as lower level ringing out to 10,000 Hz.
The knee of the SRS can be adjusted from 1000Hz to 2000Hz to meet the demands of your pyrotechnic shock test requirements.
In our lab, the test item size is NEVER an Issue. Items as small as an integrated circuit to as large as 3400 kgs (7,500 lbs), are subjected to various shock testing methods, such as the shaking profile of a truck on a potholed road, the shock of a torpedo hitting a submarine or the controlled explosions on a spacecraft.
Dynamic Design Analysis Method for Shock Design
DDAM stands for Dynamic Design Analysis Method which is a U.S. Navy standard procedure for shock design. Shipboard equipment must satisfy stringent maritime and naval requirements for durability, shock resistance, and functionality.Typically DDAM method is used to analyze the shock response at the mountings of shipboard equipment, like masts, rudders, propulsion shafts etc, due to underwater explosions. All mission-essential equipment on board surface ships and submarines must be qualified for shock loads, such as from depth charges, mines, missiles, and torpedoes.
Traditional DDAM analysis is a manual procedure in which results from frequency response analysis are post processed to provide an estimate of shock resistance. But with current finite element analysis simulation software the analysis can also be performed using commercially available FEA codes.
DDAM simulates the interaction between the shock-loaded component and its fixed structure. DDAM takes this effect into account in relation to the weight of the equipment, mounting location and orientation of the equipment on the vessel.
ANSYS provides an efficient means to perform DDAM simulation through an intuitive, interactive user interface, automatically generating the associated reports as specialized output data and tables. After performing a natural frequency analysis to determine the mode shapes and natural frequencies, a DDAM analysis is performed using an input spectrum of displacements or accelerations.
The input spectrum values are provided automatically by the software. Optionally, you can provide user-defined coefficients, which can be for an alternate unit system.
The DDAM analysis processor uses the Naval Research Laboratory (NRL) summation method to combine the peak responses from all mode shapes into overall displacements and stresses. Results can be viewed for each mode shape and the resultant in the Results environment.