·Table of Contents
Automation of Wear Analysis for Large Caliber Weapons
Dominick Salafia, Norberto L. DeLeon, and James F. Outlaw
Metrology & Simulation Division
Materiel Test Center
U. S. Army Yuma Proving Ground
Yuma, Arizona 85365
As part of the Test and Evaluation Command (TECOM) the Metrology and Simulation Division (MT-MS) at the U. S. Army Yuma Proving Ground (USAYPG) has the mission to measure and record the wear effects of conventional and experimental munitions on large caliber weapons. The primary objective is to ensure that the weapon to be fired will safely meet the mission requirements for the quantity and energy of the munitions under live fire testing. Currently, there are two criteria used to "deadline" a weapon. One is the actual physical wear tolerance. The other relates to the energy (zone) expended by the round and the subsequent fatigue induced in the microstructure of the gun tube. The latter is referred to as the Equivalent Full Charge (EFC) for the particular round. In order to maximize safety and reduce the time required to manually search records for the appropriate level of useful life, the Measurements and Simulation Branch of MT-MS at USAYPG has made use of the installation network such that critical information may be accessed from the local area network or the Internet. An electronic database has been constructed and the query routines have been written so that systems test personnel, test directors (TD), and other government organizations may conduct a search for a particular weapon. The user may enter specifications such as percent physical life, percent EFC life, caliber, model, modifications, and serial number or any combination thereof. This paper is intended to inform the engineering and scientific community, engaged in weapons performance evaluation using simulations and field testing, of the existence of wear analysis automation for large caliber weapons.
Historically, test directors, Metrology, maintenance personnel, and gun crews have had to exchange information via the form DA2408-4 Weapon Record Data Card. Our mission at Yuma Proving Ground is to conduct performance testing on a variety of munitions. Therefore, regulation dictates that maintenance records are kept using the 2408-4. For each gun tube two cards must be on file, a master and a field copy. Physical measurements are required as per the maintenance schedule set forth by regulation and/or as dictated by mission. The results of these measurements are manually annotated on each card and used to determine the percent of physical wear (useful life). The second criterion is to gage the effect of experimental munitions on the weapon. The EFC is a weighted vector whose value is determined by the type and amount of explosive charge in the munition. Subsequently a calculation is performed to estimate the remaining number of EFC rounds that may be fired. In addition, as part of our mission at YPG, certain gun tubes are modified to accept ballistic pressure transducers that are locally designed and fabricated. The location of the modifications is selected to maximize the accuracy and response of the transient pressure for a particular class or type of munition. This paper will first, define the key activities and describe the system in use before the implementation of the automated database. Secondly, the incorporation of the automated system will be examined, and finally, future plans to expand the scope of this automation will be discussed.
As mentioned earlier in the body of this dialogue the focal point for all parties concerned is the form DA 2408-4 Weapon Record Data. When a weapon is received by USAYPG a Weapon Record Data Card (master copy) is required to be shipped with it. The activity that is responsible for the issuance and maintenance of weapons checks the shipment for the presence of a master copy of form 2408-4. If so, the card is forwarded to this activity, checked for completeness, and the master copy in the local card file is amended accordingly. In the event that no card is present, a manual search of existing records is initiated. This often involves a phone conversation with other installations that have used the weapon in question, thereby initiating a manual search by the respective installation.
The final contingency is where all search efforts have been exhausted. In this event a new 2408-4 is generated listing zero rounds fired and states that there is no history for this weapon. This effectively limits the use of this weapon in terms of developmental testing. The second phase of the operation is to examine the mission at USAYPG. When the TD contacted Metrology with specifications for a weapon, a manual search of the card file was conducted and lists of weapons that meet the criteria were forwarded. This process was time consuming and cumbersome, often involving more than one person. As a result of the manual search the TD was provided with a list of weapons that met specifications. The TD then selected the weapon to be fired. If any physical measurements are required to be conducted the required measurements are performed and the master and field copy were annotated accordingly.
During the actual firing mission the TD has the responsibility to manually enter the quantity and type of round fired. Upon completion of the firing mission the field copy was checked for accuracy, and the master copy was annotated accordingly. Finally, both copies of the 2408-4 were returned to the main card file.
Some of the problems inherent in this system are primarily based on the amount of manual operations required and the lack of clear interdepartmental correspondence. The next portion of this paper describes the implementation of the automated system.
THE AUTOMATED SYSTEM
The system used at USAYPG takes full advantage of the installation's network and windows based programming. Special routines were written to accommodate the special needs of Metrology, maintenance, and TD's. In order to ensure the veracity of the database each respective party may edit the specific parameters pertaining to their responsibility.
Since the main card file is located in the Metrology Lab this activity has the primary responsibility to ensure that the database is accurate and current. Thus, serving as a nexus for required services. Figure 1 is a functional diagram of the system. As indicated in the diagram above the primary database is stored on a shared drive that resides in the Metrology Lab. Note that each respective activity has independent and simultaneous access to the query engine. This effectively eliminates the need to manually search records. Secondly, since the system supports many users, test directors and maintenance personnel may request information or update the database in a multi-user environment. At this point let us examine the functionality of the query engine with respect to each of the principle activities involved. The Artillery Systems Test Branch (ASTB) has the responsibility to provide the weapon requested by test directors, and to manage the existing inventory to maximize the useful life of a weapon. Let us first examine the query engine from the point of view of the test directors, ASTB, and the Metrology Lab. Since the test directors are the primary users of the database we will begin this discussion by examining the options available via the search engine. As shown in Figure 2 the test director first chooses the caliber of the weapon to be used in a firing mission. Selecting a caliber produces the following menu.
This search results in a list of tubes overdue physicals in ascending order. Selecting any of the above options produces a spreadsheet of the entire inventory that meets the search criteria. If the user wishes to view the data pertaining to a single record he/she simply clicks on the record in question. The spreadsheet data for %EFC and %Physical life may be represented as a bar chart.
Fig 2: |
Selecting a single record produces the following:
From the main menu, personnel from this activity may select the option to update the location of a weapon and activity status.
Metrology & Simulation Division
As stated earlier, this activity is responsible to maintain the database and has full editing privileges. When the form 2408-4 returns from the firing mission the data recorded on the card is checked for accuracy. Depending on what type of munitions fired and the caliber of the weapon an on-line calculator is provided to aid the data entry operator to update the %Physical life and %EFC life. The calculation programs are a useful tool for simulating the effects on the weapon when a variety of munitions are to be tested.
The system is working quite well at USAYPG. Most of the manual processes have been eliminated as well as any associated duplication and level of effort. Tangible and intangible cost savings have been realized. With a simple query of the database, the Metrology Lab may examine the inventory and effectively schedule any work needed thereof. Working hand in hand with ASTB personnel ensures minimal delay in the testing mission. Test directors can easily query the active inventory for the specification required. This has dramatically reduced the time required to locate a weapon and ascertain its status. The use of on-line calculators has significantly reduced the time required to update the database and provide a means to predict the effects of firing missions involving experimental munitions. Further expansion of the system involves the digitization of the 2408-4. As the information network at USAYPG expands, the concept of real time updates has become our objective. By taking advantage of current technologies, USAYPG may offer this capability to other installations with similar missions. The bottom line is that the soldier in the field and the taxpayer reap a benefit. This is the primary mission of USAYPG.
- HQ, Dept. Of Army & Air Force, TM9-1000-202-14: TO11W2-17-5-1
- Salafia et al, "Automation of Wear Analysis for Large Caliber Weapons", AIP Conference Proceeding #497,1999,pp 346-351