The invention relates to a device and method for detecting the grout compactness of splice sleeve, the device comprising a preloading member, a force transmission rod, a telescopic adjustment member, a vibration sensor and a data acquisition system. The rigid preloading member is used to fix the force transmission rod to the wall where the connecting structure of the splice sleeve is located, so that the end of the force transmission rod can be securely fastened to a rebar surface of a splice sleeve to be detected; the vibration sensor is fixed to the force transmission rod; the data acquisition system is used to acquire vibration signals from the vibration sensor. The grout compactness of splice sleeve is quantitatively analyzed, and a time-domain and frequency-domain signal may be used to obtain a peak-to-width ratio R.sub.Npw and a peak frequency Ω.sub.Peak signal to serve as a standard for the quantitative analysis.

The disclosure relates to a vertical Hopkinson pressure bar test device and a test method. The device comprises a guide cylinder, an incident bar, a transmission bar, a buffer bar and a striker, and further comprises a base; side support plates arranged vertically and upwards are provided symmetrically on two sides of the base, a horizontal first lateral support plate is provided at the top between the side support plates on the two sides, three groups of horizontal second lateral support plates are provided below the first lateral support plate sequentially between the side support plates on the two sides, and each group is provided with a clamping mechanism clamping a corresponding incident bar, transmission bar or buffer bar; the surfaces of the incident bar is pasted with a first strain gauge pad and the transmission bar is pasted with a second strain gauge pad. According to the disclosure, the striking velocity is accurately controlled to render a medium or low velocity for analyzing the dynamic mechanical properties of low-wave impedance materials such as coal and light concrete, satisfying the requirements of dynamic tests on high, medium and low velocities.

A window drop test apparatus includes a support protruding in a first direction from the prop, and a guide portion that defines a drop space together with the support, where a drop test is performed through the drop space.

A method of measuring millisecond-scale blast and impact characterization in soft materials includes embedding one or more sensors in soft material, wherein the one or more sensors have mechanical properties approximately matching the soft material; applying a constant current to the one or more sensors; subjecting the soft material to a shock or impact event; measuring a response as a change in voltage; and converting the measured voltage to strain or pressure.

A device for assessing the solidity of a material comprising an ancillary tool (2) having an end (2B) in the form of a point or blade, an impactor (4) for striking the ancillary tool (2), a sensor (12) and a processing unit (30). The ancillary tool (2) is placed between a material (8) and the impactor (4) and transmits the impact force generated by the impactor (4) to the material (8). The sensor (12) is capable of measuring a quantity from among the impact force and the deformation of the impactor, and of supplying a measurement signal. The processing unit (30) is suitable for calculating, from the measurement signal, an indicator representative of the solidity of the material (8). The indicator corresponds to the duration of a time window between the first peak (P1) of maximum amplitude of the measurement signal and the second peak of maximum amplitude (P2).

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.

Provided are a striking device and a natural frequency measuring device capable of simply and accurately measuring a natural frequency of a system including force detector. The striking device includes an arm capable of swinging around a spindle, and a steel ball arranged in an end part of the arm on a side opposite to the spindle. The spindle is supported by a supporting part capable of lifting up and down relative to a post erected on a magnet stand. A supporting part for supporting a supporting plate is arranged at a position in the post and above the supporting part. A permanent magnet is placed above the supporting plate. The steel ball falls down in an arc shape from a standby height position when the permanent magnet is removed.

A system for evaluating a bond includes first and second electrodes. A dielectric material layer is positioned at least partially between the first and second electrodes. A power source is connected to the first and second electrodes. The power source is configured to cause the first and second electrodes to generate an electrical arc. The electrical arc is configured to at least partially ablate a sacrificial material layer to generate a plasma.

An exemplary crash gate to guard against motor vehicles crossing a roadway in a direction from an attack side to a protected side including a buttress post assembly secured below ground in a first concrete foundation on a side of the roadway, the buttress post assembly having two buttress posts forming a barrier passage, a latch post assembly secured below the ground in a second concrete foundation on an opposite side of the roadway, the latch post assembly having two latch posts forming a latch gap, a barrier with a gate beam disposed in the barrier passage and extending from a buttress end to a latch end, and one of a vertical pin or a hook connected to the latch post assembly and positioned in the latch gap and the other one of the vertical pin or the hook located on the latch end, when the barrier is in a closed position the latch end is located in the latch gap and the vertical pin is positioned outside of the hook.

Provided are thermally insulating components that include sealed joints between the walls that define an insulating space therebetween. Also provided are related methods of forming and using the disclosed components.