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.

One example is a shock gauge system for measuring an external blast to a hull. The shock gauge system includes at least one accelerometer to produce acceleration data in response to the external blast, a mass with an accelerometer affixed to it, a crush block, a linear displacement potentiometer (LDP), a camera, and a processor logic. The LDP device generates displacement data of a mass being pushed into the crush block when reacting to the external blast. The camera captures images of movement of the mass. The processor logic verifies if the acceleration data is valid by correlating the acceleration data to the displacement data, the images, and/or an amount of displacement into the crush block by the mass. When the acceleration data is valid, the acceleration data may be used to create a more blast resistant hull.

A system for reconstruction of an explosion blast loading on a subject can include at least two pressure sensors and a computing system configured to: receive sensor data from the at least two pressure sensors, the sensor data being generated in response to an explosion blast wave; compute an explosion location and explosive charge mass of an explosive that caused the explosion blast wave based on the sensor data; and compute explosion blast loading on a subject from the explosion location and explosive charge mass. The pressure sensors can be configured as wearable pressure sensors or on equipment. The computing of the explosion location and explosive charge mass includes processing the sensor data through an inverse problem solver (IPS); and/or the computing of the explosion blast loading on the subject includes simulating the explosion blast wave with a forward problem solver (FPS).

A method and apparatus for testing the response of protective headgear 104 to impact forces. A high-speed cineradiography imaging system 100 is used to obtain full-field, time-resolved internal monitoring and measurement of headgear component (pads 140 and liners 142) deformation and interaction with a head surrogate (headform 102), deformation of headform components, and stress and strain transfer into the headform. Radiopaque contrast materials (144 & 148) and integration techniques are used to highlight specific regions of interest within the headgear and headform components during the impact loading events.

A method and apparatus for testing the response of protective headgear 104 to impact forces. A high-speed cineradiography imaging system 100 is used to obtain full-field, time-resolved internal monitoring and measurement of headgear component (pads 140 and liners 142) deformation and interaction with a head surrogate (headform 102), deformation of headform components, and stress and strain transfer into the headform. Radiopaque contrast materials (144 & 148) and integration techniques are used to highlight specific regions of interest within the headgear and headform components during the impact loading events.

The invention provides a method and system for a blast-induced vibration monitoring of a tunnel in high asymmetric in-situ stresses. According to the method, triaxial vibration sensors are respectively fixed in areas having different radial depths inside surrounding rocks of a stress concentration area behind a tunnel face of the tunnel in high asymmetric in-situ stresses, and each triaxial vibration sensor monitors blast vibration velocity and acceleration at a position thereof. The system comprises a plurality of triaxial vibration sensors which are fixed in areas having different radial depths inside surrounding rocks of a stress concentration area behind a tunnel face of the tunnel in high asymmetric in-situ stresses, and each triaxial vibration sensor is used for monitoring blast vibration velocity and acceleration at a position thereof. The method and system can improve the safety and the efficiency of tunnel excavation construction.

The invention provides a method and system for a blast-induced vibration monitoring of a tunnel in high asymmetric in-situ stresses. According to the method, triaxial vibration sensors are respectively fixed in areas having different radial depths inside surrounding rocks of a stress concentration area behind a tunnel face of the tunnel in high asymmetric in-situ stresses, and each triaxial vibration sensor monitors blast vibration velocity and acceleration at a position thereof. The system comprises a plurality of triaxial vibration sensors which are fixed in areas having different radial depths inside surrounding rocks of a stress concentration area behind a tunnel face of the tunnel in high asymmetric in-situ stresses, and each triaxial vibration sensor is used for monitoring blast vibration velocity and acceleration at a position thereof. The method and system can improve the safety and the efficiency of tunnel excavation construction.

The invention provides a method and system for a blast-induced vibration monitoring of a tunnel in high asymmetric in-situ stresses. According to the method, triaxial vibration sensors are respectively fixed in areas having different radial depths inside surrounding rocks of a stress concentration area behind a tunnel face of the tunnel in high asymmetric in-situ stresses, and each triaxial vibration sensor monitors blast vibration velocity and acceleration at a position thereof. The system comprises a plurality of triaxial vibration sensors which are fixed in areas having different radial depths inside surrounding rocks of a stress concentration area behind a tunnel face of the tunnel in high asymmetric in-situ stresses, and each triaxial vibration sensor is used for monitoring blast vibration velocity and acceleration at a position thereof. The method and system can improve the safety and the efficiency of tunnel excavation construction.

The invention provides a method and system for a blast-induced vibration monitoring of a tunnel in high asymmetric in-situ stresses. According to the method, triaxial vibration sensors are respectively fixed in areas having different radial depths inside surrounding rocks of a stress concentration area behind a tunnel face of the tunnel in high asymmetric in-situ stresses, and each triaxial vibration sensor monitors blast vibration velocity and acceleration at a position thereof. The system comprises a plurality of triaxial vibration sensors which are fixed in areas having different radial depths inside surrounding rocks of a stress concentration area behind a tunnel face of the tunnel in high asymmetric in-situ stresses, and each triaxial vibration sensor is used for monitoring blast vibration velocity and acceleration at a position thereof. The method and system can improve the safety and the efficiency of tunnel excavation construction.

A system of monitoring vibration of a blasting model test for a jointed rock mass and a method are provided. The system includes: a loading subsystem for three-way load, a model-surface blasting-vibration acquisition subsystem, and a model-interior dynamic stress-strain acquisition subsystem. The system and the method are provided, and a blasting model for a transparent jointed rock mass and a monitoring method that are obtained can analyze the influence of a joint inclination angle on propagation and attenuation laws of blasting stress waves in the jointed rock mass, and can analyze the influence of different millisecond blasting modes on the stability of an existing tunnel in the jointed rock mass, and can capture a real-time dynamic evolution process of cracks. The stress and strain measurement technologies used can perform omnibearing monitoring and recording for large deformations of surrounding rock under blasting load, and can resist the electromagnetic interference.