A personal ballistic protection device incorporates multiple removable test coupons. Each of the test coupons are retained with the ballistic device during its use until each coupon is removed for test purposes. Each test coupon has a construction identical to the protective portions of the ballistic device and is removable and configured to allow for destructive testing. Sufficient coupons are provided with the ballistic protection device to allow for periodic testing over a predetermined useful life of the ballistic protection device. One embodiment of the device is a body armor vest.

A personal ballistic protection device incorporates multiple removable test coupons. Each of the test coupons are retained with the ballistic device during its use until each coupon is removed for test purposes. Each test coupon has a construction identical to the protective portions of the ballistic device and is removable and configured to allow for destructive testing. Sufficient coupons are provided with the ballistic protection device to allow for periodic testing over a predetermined useful life of the ballistic protection device. One embodiment of the device is a body armor vest.

A method for testing a helmet for effectiveness of user protection includes moving a load along a predetermined path, supporting a target body at an impact location in the predetermined path, the target body including a head model and a helmet disposed on the head model, and impacting the target body with a force generated by the moving of the load. The impacting of the target body entails contacting the target body with an impactor free to move perpendicularly and tangentially relative to a surface of the target body. The supporting of the target body is at least reduced, if not eliminated, before or during the impact of the impactor with the target body at the location. Forces generated are automatically measured or sensed during the impact of the impactor with the target body at the location.

A method for testing a helmet for effectiveness of user protection includes moving a load along a predetermined path, supporting a target body at an impact location in the predetermined path, the target body including a head model and a helmet disposed on the head model, and impacting the target body with a force generated by the moving of the load. The impacting of the target body entails contacting the target body with an impactor free to move perpendicularly and tangentially relative to a surface of the target body. The supporting of the target body is at least reduced, if not eliminated, before or during the impact of the impactor with the target body at the location. Forces generated are automatically measured or sensed during the impact of the impactor with the target body at the location.

A deformation mode analysis method for a member of a structure is a method of analyzing a deformation mode of each member by performing structural analysis or a structural test on a structure including a single member or a plurality of members. In this method, the deformation mode of the structure is analyzed by separating the structure into a plurality of regions and calculating deformations for every separated region.

A method of detecting a preload of a linear guide includes: applying an external force to the linear guide with an external force applying device, wherein the external force applying device sends an impact signal while applying the external force; sensing with a sensor a vibration signal sent from the linear guide because of vibration thereof which occurs under the external force; and receiving the impact signal of the external force applying device and the vibration signal of the sensor and calculating the preload of the linear guide according to a received result, with a signal analyzer. Therefore, with the method of the present invention, the preload of the linear guide is precisely tested regardless of environmental factors.

A method of detecting a preload of a linear guide includes: applying an external force to the linear guide with an external force applying device, wherein the external force applying device sends an impact signal while applying the external force; sensing with a sensor a vibration signal sent from the linear guide because of vibration thereof which occurs under the external force; and receiving the impact signal of the external force applying device and the vibration signal of the sensor and calculating the preload of the linear guide according to a received result, with a signal analyzer. Therefore, with the method of the present invention, the preload of the linear guide is precisely tested regardless of environmental factors.

An impact sensor is mounted in a duct of a grain cleaning system above an upper sieve. The impact sensor has an upstream-facing impact-sensing surface with respect to a cleaning airstream, and is configured to transduce impact events and generate impact signals therefrom. An electronic control unit (ECU) is configured to generate control signals based upon a particle energy value that is determined from the impact signals. The control signals may serve to adjust various working units of a combine harvester including, by way of example, a cleaning fan and sieves.

Milling tools and methods are disclosed. The method may include moving a milling tool having at least two axially spaced apart sets of cutting inserts to an axial position within a bore in a material and rotating the milling tool about a longitudinal axis. Contact between the milling tool and a wall of the bore may be initiated in a region of the wall having a least amount of material at the axial position. The milling tool may include a tool shaft having a longitudinal axis, a first set of radially spaced cutting inserts coupled to the tool shaft, and a directly adjacent second set of radially spaced cutting inserts coupled to the tool shaft and spaced from the first set of cutting inserts along the longitudinal axis. The first and second sets of cutting inserts may be staggered from each other by at least 10 degrees.

Milling tools and methods are disclosed. The method may include moving a milling tool having at least two axially spaced apart sets of cutting inserts to an axial position within a bore in a material and rotating the milling tool about a longitudinal axis. Contact between the milling tool and a wall of the bore may be initiated in a region of the wall having a least amount of material at the axial position. The milling tool may include a tool shaft having a longitudinal axis, a first set of radially spaced cutting inserts coupled to the tool shaft, and a directly adjacent second set of radially spaced cutting inserts coupled to the tool shaft and spaced from the first set of cutting inserts along the longitudinal axis. The first and second sets of cutting inserts may be staggered from each other by at least 10 degrees.