A03 - Miscellalneous Requirements - Purchase Requirements for Drop Weight Impact Tester.pdf

Purchase Requirements for Drop Weight Impact Tester

1. General

This contract will cover the purchase, installation, and training of a drop weight impact tester.

2. Background

The Materials and Measurements Test Branch (MMTB) is part of the US Army Aberdeen Test Center (ATC). The Branch supports the entire Test Center with materials testing as well as metrology measurements. ATC and the MMTB has a need for a drop weight impact tester.

The US Army uses mechanical pressure gauges to acquire chamber pressure measurements in large caliber weapon systems that allow the measurement of pressure without having to alter the weapon at all. The gauges rely on a calibrated copper sphere to be crushed proportional to the pressure inside the chamber. The copper spheres require calibration to ensure that they provide good data.

In the past, ATC has had multiple systems dedicated to the calibration of copper crusher spheres. These systems only purpose was to calibrate gauges and spheres, and when they sat for too long unused, they were turned in and scrapped. ATC no longer has the ability to calibrate spheres, but the requirement still exists. The way these systems work, is that a vessel is made to hold the gauges, and a mass is impacted on an exposed piston in the vessel. The vessel being filled with fluid, is quickly pressurized simulating a firing event in a large caliber weapon system. The drop tower is needed to provide the impact energy required to pressurize the system.

Additionally, the MMTB is a materials lab, and performs standard materials tests such a tension, compression, cyclic fatigue, metallography, composition analysis, and hardness. About 15 years ago, the MMTB had a pendulum Charpy test machine that broke down and was never fixed nor replaced. There are multiple requests every year for standard impact tests such as Charpy and Izod that are unable to be fulfilled. There are also multiple requests for end item impact tests that a drop tower would be extremely useful for.

This Purchase Request is to provide a drop tower as a means of calibrating the copper crusher gauges, but it will also not be SOLELY dedicated to that purpose. This item will have many other tests that it can support and therefore should not be turned in like previous calibration testers.

3. Scope

The scope of this contract is to purchase a Drop Weight Impact Test system. The purchase will include the installation and training of the new drop tower system. It will also include all hardware and software needed to run and use the equipment except the PC. ATC will provide a computer that will be used for the drop tower system.

4. Place of Performance

The Drop Weight Impact Tester will be installed in the MMTB lab located in building 400, APG, MD. The contractor must travel to the site to install the equipment.

5. Drop Weight Impact Test System Requirements

a) Drop Weight Impact Tester

The MMTB is requesting a drop weight impact test unit.

The drop tower must be able to provide impact energies up to 2,000 Joules. The old copper sphere test instruments provided the basis for this energy requirement.

The overall height of the drop tower must be less than 16 feet due to the building.

The drop tower must come with enough weights to test at a variety of energies. The weights must be in at least 1 kg increments up ot the maximum load.

The test area must be able to accommodate custom made test fixtures and samples.

A t-slotted table/platform is required to accomplish this task. The impact tester will be used to impact finished items, components, and the calibration vessel so a flexible mounting platform is a must. The mounting table must be at least 24”x24” in size.

The test chamber should accommodate specimens and fixtures up to 24” in height.

The drop weight impact test system must have rebound control system that prevents a second impact when used.

b) Temperature Chamber

The drop tower must include a temperature chamber capable of hot and cold conditions. The chamber must have a range of at least -70°F to 170°F.

The temperature chamber must be able to be removed and installed easily without the need for lifting equipment.

The temperature chamber must be able to accommodate items up to 12”x12”x12” in size.

The compressive properties of the spheres change with temperature, so this requirement is very important.

c) Tups/Load Cells, and Strikers

A piezo load cell for Izod and Charpy tests is required. The max force of the load cell should be close to 10kN.

Charpy Striker is required Izod Striker is required

d) Standard Test Fixtures

The drop tower must come with mounts capable of testing Charpy samples and Izod samples. All items needed to perform these tests must be included.

e) Installation and Training

Installation and Training must be provided onsite (Building 400)

f) Testing Software

Software to run the machine will be provided.

g) Experience

The instrument that is purchased must be from a company that has made drop weight impact test systems for at least 5 years.

The vendor must be able to provide a yearly maintenance and calibration service to the machine.

6. ATC POC for this purchase request:

Aberdeen Test Center

ATTN: Benjamin Hardisky

TEAT-WFA

Building 400, 6943 Colleran Rd Aberdeen Proving Ground, MD, 21005 Phone (410) 278-3258 Email: benjamin.l.hardisky.civ@mail.mil