Armor Durability and Reliability Testing
DTB can perform all Mil 810 G, ATPD 2352, NIJ 0101.06 and NIJ 0108 environmental and ballistic armor tests. No other private lab in the country can make this claim. Recent experience has shown that standardized tests are not always enough to ensure failure free operation of armor after exposure to repeated environmental and vibration or shock cycles.
DTB develops customized accelerated life test protocols to simulate worse case conditions for a variety of different types of armor. Whether the armor is metallic, polymeric or ceramic, we can derive an appropriate accelerated life test to simulate over a decade of field use.
Armor Aging – Impetus
Two Primary Reasons to Study Armor Aging:
- Input for Design, Materials Selection, and Processing to decelerate the damage
- To understand the degradation kinetics and pathways for the current configuration
Armor Aging – Investigation Difficulties
Biggest practical concern/issue
- How to Correlate the test results to service life
- Generally requires a large number of very expensive and time-consuming tests
Typical Armor Configuration
Typical Armor Configuration
- Macro-composite with multiple interfaces
- Time-dependent degradation of this macro-composite system
» Depends on the sum of three principal factors
- Interfacial processes
- Degradation of the bulk
- Degradation of the barrier
- The weakest link will control the overall response
Armor Configuration Example
Armor Aging – Building Block Approach
- Separate the damage mechanisms based on Armor configuration
- Determine the rate controlling degrader and the rate controlling location
- Determine the damage kinetics for the rate controller
- Provide property deltas as inputs to analytical/numerical model(s)
- Estimate system response as a function of usage TIME
Armor Aging – Fundamental Considerations
Armor Aging – Intrinsic Effects
- Degraders
- Temperature
- Stress
- Moisture
- UV
- Vibration
- Shock
- Chemical: Salt, Oxygen
- Investigate degradation kinetics for each degrader (as appropriate)
- Superposition through appropriate numerical modeling analytical/numerical modeling
Armor Aging – Interaction Effects
- Degraders
- Interfacial reactions
- Interfacial stress accumulation
- Temperature
- Stress
- Moisture
- Investigate degradation kinetics for each degrader
- Compare Intrinsic and Interaction rates
Armor Aging – Test Considerations
- At the test level, the main issues are
- How to measure aging
- How to accelerate the process of aging so that a measurable response can be attained
- How to analyze the data in order to isolate the weakest link in the configuration (fastest degrading location)
- In practical terms, it is useful to focus on properties that respond to the sum total of all the aging processes rather than the mechanistic details of aging
Armor Aging – Sum Total Response Measurement (Toughness)
Armor Aging – Tests
- Tests that use a Sum total of the Response
- Impact (energy absorbed)
- Interfacial shear
- Fiber push-out
- Off-gassing products (GC/QMS)
- Weight gain/loss
- Microfractography, fracture path analysis
- Stereological measurements
- Diffusional gradients (not preferred)
- Others….
Armor Aging - Kinetics
- Determine the weakest link in terms of the damage rate control location
- Determine the rate-controlling degrader for the weakest link
- Thermal
- Thermal cycling
- Mechanical stress
- Environmental stress (e.g. corroding ions..)
- ….
System Response – Through Modeling
- Modeling is a key element of the current approach
- Just because the fastest degrader and its rate is known, does not imply that the system response is known
- For example, a 10% degradation of a parameter may not translate into a 10% change in the Armor response
- That change MUST be derived from a valid analytical/numerical model
- What IS known, however, is the time dependence of the response
Armor Aging – Inputs To Modeling
- Validate through selected full-scale ballistic response testing
Dtb Capabilities – Armor Testing
- Accreditations/Certifications
- A2LA
- ISO 9001 Registered
- AS9100 Registered
- NVLAP
- NIJ0307.01 Handcuff/Restraints Testing
- NIJ 0101.06 Body Armor Testing
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- Testing Standards
- ATPD Transparent Armor
- MIL-P-48655AR Handgun Testing
- TOPS3-2-045 Small Arms
- Rifles and Machine-guns
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- Commodities/Services
- Small arms up to .50 caliber
- Small arms ammunition up to .50 caliber
- Small arms components and accessories
- Select medium caliber
- Terminal ballistics
- Armor plating
- Personal protective equipment
- Live fire evaluations
- Training facility for military and law enforcement personnel
- Safeguarding, accountability, security and safety systems for small arms and ballistic test programs that are approved by the DoD and compliant with:
- DoD Manual 5100.76
- DoD Manual 4145.26
- DoD Manual 5122.22
- FAR Part 45—Government Property Federal, state and local licensing requirements are met
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