The present disclosure discloses a method for calculating an internal explosion load speed based on an incremental crack growth distance of a pipeline. The method includes steps of: respectively measuring at least three groups of distances between neighboring markings on forward and backward crack surfaces, and calculating the average values respectively to obtain the average incremental growth distances of forward and backward cracks; calculating the natural vibration frequency of the pipeline; and setting the ratio of backward crack speed to forward crack speed of the pipeline, then calculating the internal explosion load speed of the pipeline by a formula. The present disclosure provides a new effective method for calculating the internal explosion load speed based on the available parameters of the ruptured pipeline after explosion, which can provide a comparatively accurate estimation of internal explosion load speed, thereby providing references for inferring the explosion type occurred in the pipeline.

The present disclosure discloses a method for calculating an internal explosion load speed based on an incremental crack growth distance of a pipeline. The method includes steps of: respectively measuring at least three groups of distances between neighboring markings on forward and backward crack surfaces, and calculating the average values respectively to obtain the average incremental growth distances of forward and backward cracks; calculating the natural vibration frequency of the pipeline; and setting the ratio of backward crack speed to forward crack speed of the pipeline, then calculating the internal explosion load speed of the pipeline by a formula. The present disclosure provides a new effective method for calculating the internal explosion load speed based on the available parameters of the ruptured pipeline after explosion, which can provide a comparatively accurate estimation of internal explosion load speed, thereby providing references for inferring the explosion type occurred in the pipeline.

A method includes determining a perforation tunnel geometry of a perforation tunnel in a solid sample, the perforation tunnel created by activating a shaped charge in proximity to the solid sample. The method also includes performing a first flow test on the solid sample and creating an analog aperture having an aperture geometry in a solid sample analog of the solid sample, wherein the aperture geometry and the perforation tunnel geometry satisfies a similarity threshold. The method also includes performing a second flow test on the solid sample analog and determining a shaped charge effect based on a comparison between a second flow test result and a first flow test result.

A method includes determining a perforation tunnel geometry of a perforation tunnel in a solid sample, the perforation tunnel created by activating a shaped charge in proximity to the solid sample. The method also includes performing a first flow test on the solid sample and creating an analog aperture having an aperture geometry in a solid sample analog of the solid sample, wherein the aperture geometry and the perforation tunnel geometry satisfies a similarity threshold. The method also includes performing a second flow test on the solid sample analog and determining a shaped charge effect based on a comparison between a second flow test result and a first flow test result.

The present disclosure discloses a method for calculating an internal explosion load speed based on an incremental crack growth distance of a pipeline. The method includes steps of: respectively measuring at least three groups of distances between neighboring markings on forward and backward crack surfaces, and calculating the average values respectively to obtain the average incremental growth distances of forward and backward cracks; calculating the natural vibration frequency of the pipeline; and setting the ratio of backward crack speed to forward crack speed of the pipeline, then calculating the internal explosion load speed of the pipeline by a formula. The present disclosure provides a new effective method for calculating the internal explosion load speed based on the available parameters of the ruptured pipeline after explosion, which can provide a comparatively accurate estimation of internal explosion load speed, thereby providing references for inferring the explosion type occurred in the pipeline.

The present disclosure discloses a method for calculating an internal explosion load speed based on an incremental crack growth distance of a pipeline. The method includes steps of: respectively measuring at least three groups of distances between neighboring markings on forward and backward crack surfaces, and calculating the average values respectively to obtain the average incremental growth distances of forward and backward cracks; calculating the natural vibration frequency of the pipeline; and setting the ratio of backward crack speed to forward crack speed of the pipeline, then calculating the internal explosion load speed of the pipeline by a formula. The present disclosure provides a new effective method for calculating the internal explosion load speed based on the available parameters of the ruptured pipeline after explosion, which can provide a comparatively accurate estimation of internal explosion load speed, thereby providing references for inferring the explosion type occurred in the pipeline.

An apparatus and a method for testing combined dynamic-static loading strength of a rock-like material are provided. The apparatus and the method can test the combined dynamic-static loading strength of the rock-like material. The apparatus comprises an explosion load loading device, a static load loading device, and a stress wave rod transferring device. The explosion load loading device is connected with one end of the stress wave rod transferring device. The stress wave rod transferring device is connected with a rock-like material specimen. The stress wave rod transferring device is connected with the static load loading device.

An apparatus and a method for testing combined dynamic-static loading strength of a rock-like material are provided. The apparatus and the method can test the combined dynamic-static loading strength of the rock-like material. The apparatus comprises an explosion load loading device, a static load loading device, and a stress wave rod transferring device. The explosion load loading device is connected with one end of the stress wave rod transferring device. The stress wave rod transferring device is connected with a rock-like material specimen. The stress wave rod transferring device is connected with the static load loading device.

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.