513.8-33 information required

MIL-STD-810H, Environmental Engineering Considerations and Laboratory Tests

Last Updated 29 Oct 2026

Hover any section to copy its link or text, ask Copilot about it, or bookmark it.

513.8-3 ACCELERATION AND FORCE CALCULATION

Figure 513.8A-4 depicts the forces due to rotation and change in rotational speed of the centrifuge.

MIL-STD-810H

METHOD 513.8 ANNEX A

Basic forces on a test item due to centrifuge-produced accelerations

Figure description:

Key Diagram Information

Subject: Basic forces on a test item due to centrifuge-produced accelerations.
Components: Centrifuge Arm, Test Item, Center of Rotation, Centrifuge Base, Counterweights.
Vector Variables: $a_t$ (tangential acceleration, $a_n$ (normal acceleration, $a_R$ (resultant acceleration, $F_t$ (tangential force, $F_c$ (centrifugal force, $F_R$ (resultant force.

Acceleration and Force Data Table

Category	Formulas	Variable Definitions
Acceleration	$a_R = \sqrt{a_t^2 + a_n^2}$	$a_R$ : resultant acceleration where normal and tangential exist $a_t = r\alpha$ : tangential acceleration $a_n = r\omega^2$ : normal acceleration $\alpha$ : change in centrifuge rotational acceleration (rad/s² $\omega$ : centrifuge rotational velocity (rad/s))
Force	$F_R = \sqrt{F_t^2 + F_c^2}$	$F_R$ : resultant force $F_t = m a_t$ : force due to tangential acceleration $F_c = m a_n$ : centrifugal force due to normal acceleration $m$ : mass of the test item
General Expression*	$g's = \frac{\pi^2 N^2 r}{900G}$	$g$ : acceleration as a number of gravity units $G$ : gravitational unit of acceleration ( $9.81\text{ m/sec}^2$ ) or $32.2\text{ ft/sec}^2$ $\pi$ : 3.14159 $N$ : revolutions per minute $r$ : radius of gyration (feet or inches)
Centimeter Units	$g's = 0.1118 \times 10^{-4} r N^2$
Inch Units	$g's = 0.2838 \times 10^{-4} r N^2$
Meter Units	$g's = 0.1118 \times 10^{-2} r N^2$
Feet Units	$g's = 0.3406 \times 10^{-3} r N^2$

*Derived from equation for normal acceleration, $a_n = r\omega^2$ .

Figure 513.8A-4. Basic forces imposed on test item due to accelerations produced by centrifuge.

Downloaded from https://www.everyspec.com

MIL-STD-810H

METHOD 513.8 ANNEX A

(This page is intentionally blank.)

MIL-STD-810H

METHOD 514.8

METHOD

3.1 Pretest

The following information is required to conduct acceleration tests adequately.

a. General. Information listed in Part One, paragraphs 5.7 and 5.9; and Part One, Annex A, Task 405 of this Standard.
b. Specific to this test Method.
(1) Vector orientation of test item with respect to the fixture.
(2) Vector orientation of fixture with respect to direction of acceleration.
(3) Photos of the test item and test setup before the tests.
(4) Center of gravity of the test item.

MIL-STD-810H

METHOD 513.8

c. Tailoring. Necessary variations in the basic test procedures to accommodate LCEP requirements and facility limitations.

3.2 During Test

Collect the following information during conduct of the test:

a. General. Information listed in Part One, paragraph 5.10; and in Part One, Annex A, Tasks 405 and 406 of this Standard.
b. Specific to this Method.
(1) Information related to failure criteria for test materiel under acceleration for the selected procedure or procedures. Pay close attention to any test item instrumentation and the manner in which the information is received from the sensors. For example, the acquisition of sensor signals from a test item on a centrifuge must consider either the way of bringing the sensor signals out through the centrifuge, a way of telemetering the sensor signals, or the effects of the acceleration on a recorder mounted on the centrifuge near the sensor for obtaining the sensor signals.
(2) Photos of the test item and test setup during tests.
(3) Record the time history of pertinent test data using a data recording device.

3.3 Post-Test

The following post test data shall be included in the test report.

a. General. Information listed in Part One, paragraph 5.13; and in Part One, Annex A, Task 406 of this Standard.
b. Specific to this Method.
(1) Vector orientation of test item with respect to the fixture.
(2) Vector orientation of fixture with respect to direction of acceleration.
(3) Photos of the test item after the tests.
(4) Record of time history pertinent test data.
(5) Any deviations from the original test plan.

513.8-33 information required

MIL-STD-810H, Environmental Engineering Considerations and Laboratory Tests

Last Updated 29 Oct 2026

Hover any section to copy its link or text, ask Copilot about it, or bookmark it.

513.8-3 ACCELERATION AND FORCE CALCULATION

Figure 513.8A-4 depicts the forces due to rotation and change in rotational speed of the centrifuge.

MIL-STD-810H

METHOD 513.8 ANNEX A

Basic forces on a test item due to centrifuge-produced accelerations

Figure description:

Key Diagram Information

Subject: Basic forces on a test item due to centrifuge-produced accelerations.
Components: Centrifuge Arm, Test Item, Center of Rotation, Centrifuge Base, Counterweights.
Vector Variables: $a_t$ (tangential acceleration, $a_n$ (normal acceleration, $a_R$ (resultant acceleration, $F_t$ (tangential force, $F_c$ (centrifugal force, $F_R$ (resultant force.

Acceleration and Force Data Table

Category	Formulas	Variable Definitions
Acceleration	$a_R = \sqrt{a_t^2 + a_n^2}$	$a_R$ : resultant acceleration where normal and tangential exist $a_t = r\alpha$ : tangential acceleration $a_n = r\omega^2$ : normal acceleration $\alpha$ : change in centrifuge rotational acceleration (rad/s² $\omega$ : centrifuge rotational velocity (rad/s))
Force	$F_R = \sqrt{F_t^2 + F_c^2}$	$F_R$ : resultant force $F_t = m a_t$ : force due to tangential acceleration $F_c = m a_n$ : centrifugal force due to normal acceleration $m$ : mass of the test item
General Expression*	$g's = \frac{\pi^2 N^2 r}{900G}$	$g$ : acceleration as a number of gravity units $G$ : gravitational unit of acceleration ( $9.81\text{ m/sec}^2$ ) or $32.2\text{ ft/sec}^2$ $\pi$ : 3.14159 $N$ : revolutions per minute $r$ : radius of gyration (feet or inches)
Centimeter Units	$g's = 0.1118 \times 10^{-4} r N^2$
Inch Units	$g's = 0.2838 \times 10^{-4} r N^2$
Meter Units	$g's = 0.1118 \times 10^{-2} r N^2$
Feet Units	$g's = 0.3406 \times 10^{-3} r N^2$

*Derived from equation for normal acceleration, $a_n = r\omega^2$ .

Figure 513.8A-4. Basic forces imposed on test item due to accelerations produced by centrifuge.

Downloaded from https://www.everyspec.com

MIL-STD-810H

METHOD 513.8 ANNEX A

(This page is intentionally blank.)

MIL-STD-810H

METHOD 514.8

METHOD

3.1 Pretest

The following information is required to conduct acceleration tests adequately.

a. General. Information listed in Part One, paragraphs 5.7 and 5.9; and Part One, Annex A, Task 405 of this Standard.
b. Specific to this test Method.
(1) Vector orientation of test item with respect to the fixture.
(2) Vector orientation of fixture with respect to direction of acceleration.
(3) Photos of the test item and test setup before the tests.
(4) Center of gravity of the test item.

MIL-STD-810H

METHOD 513.8

c. Tailoring. Necessary variations in the basic test procedures to accommodate LCEP requirements and facility limitations.

3.2 During Test

Collect the following information during conduct of the test:

a. General. Information listed in Part One, paragraph 5.10; and in Part One, Annex A, Tasks 405 and 406 of this Standard.
b. Specific to this Method.
(1) Information related to failure criteria for test materiel under acceleration for the selected procedure or procedures. Pay close attention to any test item instrumentation and the manner in which the information is received from the sensors. For example, the acquisition of sensor signals from a test item on a centrifuge must consider either the way of bringing the sensor signals out through the centrifuge, a way of telemetering the sensor signals, or the effects of the acceleration on a recorder mounted on the centrifuge near the sensor for obtaining the sensor signals.
(2) Photos of the test item and test setup during tests.
(3) Record the time history of pertinent test data using a data recording device.

3.3 Post-Test

The following post test data shall be included in the test report.

a. General. Information listed in Part One, paragraph 5.13; and in Part One, Annex A, Task 406 of this Standard.
b. Specific to this Method.
(1) Vector orientation of test item with respect to the fixture.
(2) Vector orientation of fixture with respect to direction of acceleration.
(3) Photos of the test item after the tests.
(4) Record of time history pertinent test data.
(5) Any deviations from the original test plan.