The present invention provides an experimental platform for simulating a coal rock disaster of a coal mine extraction, including a base device, a coal simulation device, an immediate roof simulation device, a hydraulic support and a removable impact device. The coal simulation device is fixedly disposed on the base device; the hydraulic support is fixed on the base device and is located at one side of the coal simulation device; the immediate roof simulation device is disposed above the coal simulation device and the hydraulic support; the removable impact device is disposed above the immediate roof simulation device; the immediate roof simulation device is a rectangular frame; the rectangular frame is configured to pave a bulk simulation material and an immediate roof simulation material sequentially from the bottom up; and the removable impact device can impact the immediate roof simulation material and the bulk simulation material.

The present invention provides an experimental platform for simulating a coal rock disaster of a coal mine extraction, including a base device, a coal simulation device, an immediate roof simulation device, a hydraulic support and a removable impact device. The coal simulation device is fixedly disposed on the base device; the hydraulic support is fixed on the base device and is located at one side of the coal simulation device; the immediate roof simulation device is disposed above the coal simulation device and the hydraulic support; the removable impact device is disposed above the immediate roof simulation device; the immediate roof simulation device is a rectangular frame; the rectangular frame is configured to pave a bulk simulation material and an immediate roof simulation material sequentially from the bottom up; and the removable impact device can impact the immediate roof simulation material and the bulk simulation material.

In a wedge looseness diagnosis which is performed by striking wedges of a rotary electric machine, a variation of a wave form of a strike sound is reduced with respect to a variation of an amount of looseness of the wedges, and it is difficult that a slight difference of the amount of the looseness of the wedges is discriminated, so that the wedges are struck by a strike portion in a state where the wedges are pressed by a pressure portion which presses the wedges, and a strike sound at a high frequency is reduced, whereby an amount of a variation of magnitude of the strike sound is enlarged with respect to a valuation of the amount of the looseness of the wedges, and the amount of the looseness of the wedges is judged in accordance with the strike sound which is obtained by a strike sound measuring portion.

In a wedge looseness diagnosis which is performed by striking wedges of a rotary electric machine, a variation of a wave form of a strike sound is reduced with respect to a variation of an amount of looseness of the wedges, and it is difficult that a slight difference of the amount of the looseness of the wedges is discriminated, so that the wedges are struck by a strike portion in a state where the wedges are pressed by a pressure portion which presses the wedges, and a strike sound at a high frequency is reduced, whereby an amount of a variation of magnitude of the strike sound is enlarged with respect to a valuation of the amount of the looseness of the wedges, and the amount of the looseness of the wedges is judged in accordance with the strike sound which is obtained by a strike sound measuring portion.

The present disclosure discloses a testing apparatus for directional simulation of dynamic collision between a deep-sea shell structure and seabed, including: a launching device, a high-pressure water pump device, a high-speed camera, a sensor system, a data collection and control system, etc. This device is installed in a geotechnical centrifuge for experiment, a super-gravity environment is provided to meet requirements of simulation of a deep-sea environment, and a deep-sea high-pressure environment is created through a high-pressure water pump device by superposition. A direction of the launching device is adjusted through a universal rotating shaft to control the shell structure to be launched from a specified direction to collide with soil at a predetermined position. A high-speed camera is used to capture an entire experiment process, and strain and acceleration sensors are used to collect experiment data.

The present disclosure discloses a testing apparatus for directional simulation of dynamic collision between a deep-sea shell structure and seabed, including: a launching device, a high-pressure water pump device, a high-speed camera, a sensor system, a data collection and control system, etc. This device is installed in a geotechnical centrifuge for experiment, a super-gravity environment is provided to meet requirements of simulation of a deep-sea environment, and a deep-sea high-pressure environment is created through a high-pressure water pump device by superposition. A direction of the launching device is adjusted through a universal rotating shaft to control the shell structure to be launched from a specified direction to collide with soil at a predetermined position. A high-speed camera is used to capture an entire experiment process, and strain and acceleration sensors are used to collect experiment data.

A braking device system for a test pendulum arrangement to perform crash test dummy certifications, the braking device system including a braking device configured to brake a moving pendulum, on which a head and neck assembly of a crash test dummy is capable of being arranged, in a lower braking region, wherein the braking device includes a plunger configured to be actuated axially by a motor arrangement which is designed to come into contact with the pendulum in a defined braking region and to brake the pendulum by a braking force exerted by the plunger.

A braking device system for a test pendulum arrangement to perform crash test dummy certifications, the braking device system including a braking device configured to brake a moving pendulum, on which a head and neck assembly of a crash test dummy is capable of being arranged, in a lower braking region, wherein the braking device includes a plunger configured to be actuated axially by a motor arrangement which is designed to come into contact with the pendulum in a defined braking region and to brake the pendulum by a braking force exerted by the plunger.

Various embodiments relating to methods for evaluating injury mitigation performance of helmets that are used for snow sports (e.g., skiing or snowboarding) are described. In one embodiment, a method for evaluating injury mitigation performance of a helmet includes applying a first and a second impact configuration to a helmet. The first and the second impact configurations include a plurality of impacts between the helmet and a metal plate. The metal plate is tilted at a first predetermined angle for the first impact configuration and at a second predetermined angle for the second impact configuration. The method further includes generating acceleration and velocity data based on impacts that occur as part of the two impact configurations. The method further includes determining injury risk values based on the generated acceleration and velocity data. The method also includes determining an overall injury risk metric based on the injury risk values and exposure values.

Various embodiments relating to methods for evaluating injury mitigation performance of helmets that are used for contact sports (e.g., rugby) are described. In one embodiment, a method for evaluating injury mitigation performance of a helmet includes applying first, second, and third impact configurations to a first helmet. The method further includes generating acceleration and velocity data based on impacts that occur as part of the three impact configurations. The method further includes determining injury risk values based on the generated acceleration and velocity data. The method also includes determining an overall risk metric based on the injury risk values and exposure values.