ASTM D3332 Standard Test Methods for Mechanical-Shock Fragility of Products, Using Shock Machines

Get Certified ASTM D3332 Testing for Reliable Mechanical-Shock Fragility Evaluation

ASTM D3332 tests can evaluate the mechanical-shock fragility of products under controlled shock conditions. Manufacturers, engineers, packaging specialists, and quality-assurance personnel can then use the results to assess product vulnerability and choose appropriate cushioning or redesign the product. Testing uses controlled shock pulses to establish critical velocity change and critical acceleration, as specified in the appropriate requirements of ASTM D3332. The data obtained can also be used to help develop damage boundary data for assessing product response in various shock directions and conditions.

• Product: Products and unit or consumer packages transported within outer containers.
• Shock condition: Controlled mechanical shock generated using a shock test machine.
• Test Method A: Determination of the product’s critical velocity change.
• Test Method B: Determination of the product’s critical acceleration.
• Damage evaluation: Examination or functional testing of the product after shock exposure.
• Shock direction: Evaluation of different directions when product orientation can change during handling impacts.
• Instrumentation: Measurement of acceleration-time histories and shock-table velocity change.
• Damage boundary: Development of information relating shock input conditions to product damage.
• Conditioning: Application of specified temperature and humidity conditioning when required.
• Units: Inch-pound units are standard, with SI conversions provided for information.

What are the Uses of ASTM D3332 Testing?

ASTM D3332 establishes a method for testing the fragility of products to provide information that can be used in packaging and product design. Manufacturers, engineers, packaging specialists, and quality-assurance personnel can use the results to evaluate product response to mechanical shock. The ASTM D3332 standard-

• Determines the critical velocity change of products.
• Checks the critical acceleration of products.
• Assesses the damage of products under controlled mechanical shock.
• Helps to choose cushioning materials for shipping containers.
• Helps make products more rugged and shock-resistant.
• Helps to make changes to product and packaging designs.
• Assesses product shock fragility in various orientations.
• Supplies information for the creation of product damage boundary information.
• Assists in quality-control and product-development programs.
• Assists in recording shock conditions, product damage, and test results.

Which materials can be tested under ASTM D3332?

ASTM D3332 applies to products, not to a class of materials, and includes unit or consumer packages that are carried in outer packages. Products can range from assembled products, packaged products, electronic equipment, consumer products, medical devices, industrial equipment, and other articles whose response to mechanical shock must be assessed. Where the aim of the test is to identify the shock conditions that can result in functional, structural, or other specified damage, the test may be conducted on the product in its intended configuration.

Why is ASTM D3332 Important?

ASTM D3332 is important because it provides standard procedures for measuring product shock fragility via critical velocity change and critical acceleration testing. The standard specifies controlled shock conditions and includes requirements for instrumentation, product mounting, measurement of shock pulses, and damage evaluation. Test Method A is a shock pulse of duration not exceeding 3 ms to determine critical velocity change, and Test Method B is a trapezoidal shock pulse with rise and fall times of 1.8 ms or less, normally used to determine critical acceleration. These measurements give quantitative data to help in the selection of cushioning materials, in designing products, and in assessing the performance of mechanical shock.

ASTM D3332 Testing Process and Data Collection

ASTM D3332 requires the prepared product to be securely mounted and subjected to controlled shock pulses, during which technicians record acceleration-time histories and velocity-change information. In Test Method A, the shock pulse duration should not exceed 3 ms, and the velocity change is increased until product damage occurs. Test Method B holds the velocity change at or above the required level and increases the maximum faired acceleration until damage occurs. Analysts document the shockwave, max faired acceleration, pulse duration, velocity change, drop height, product condition, and observed damage. The data is then used to determine critical shock characteristics and to aid in developing a product damage boundary.

Common Challenges and Troubleshooting

Problems with ASTM D3332 are related to the following: Improper product mounting, unsuitable support points, incorrect shock-pulse characteristics, instrumentation error, secondary shock, orientation changes, and inconsistent damage evaluation. Thus, the product configuration, fixture rigidity, mounting points, accelerometer installation, velocity-measurement system, and shock-machine settings should be checked by technicians before testing. It should also be sufficiently rigid not to distort the shock pulse applied to the product, and the carriage should be arrested after impact to prevent secondary shock. The recorded pulse should also be analyzed to ensure that the necessary velocity change and acceleration were attained. To increase the reliability of the results, proper orientation and functional inspection are performed.

• The laboratory provides the necessary information regarding the critical velocity change for the product and tested direction.
• The analyst checks the shock pulse duration and velocity-change measurement for Test Method A.
• The laboratory evaluates critical acceleration for each tested product direction when Test Method B is required.
• Engineers compare the recorded shock-pulse characteristics with the intended test conditions.
• Analysts evaluate product damage through visual inspection, functional testing, or both.
• The laboratory checks the product’s mounting configuration and support points during testing.
• Engineers record the acceleration, pulse duration, velocity change, and drop height that cause damaging shocks at their maximum levels.
• Analysts then use the critical values measured to help select cushioning materials and modify product designs.
• The laboratory records damage-boundary data and other conditioning and sampling data for traceability.

Link to ASTM D3332