An equivalent test method of a piston vibrating machine and a rocker-arm vibrating machine applied in half breakdown time test, including: selecting three grades of samples in the same size specification; separately selecting frequencies of the piston vibrating machine and the rocker-arm vibrating machine; estimating impact times of the two vibrating machines for three grades of samples; setting up the impact times and separately impacting the samples with the two vibrating machines; sieving and weighing the impacted samples and obtaining the unbroken ratios; calculating impact cycles with an unbroken ratio of 50%; calculating the ratios of the impact cycles of the two vibrating machines for the samples; calculating an average of the ratios; calculating the relative percentages of impact cycle ratios for the three grades and assessing the linearity of the samples; and calculating equivalent impact cycles of the vibrating machines.

The present invention provides a standard testing methodology for making quantitative determinations as to the chemical resistance of thermoplastics commonly used for non-disposable medical devices by evaluating the retention of tensile and/or impact properties of the thermoplastic materials after exposure to chemicals associated with healthcare grade disinfectants. Versions of the test methods may be used with any of a variety of different thermoplastic materials, each having a different stiffness or elastic modulus; and versions of the test methods may be used with any of a variety of different hospital grade cleaning agents or disinfectants. Using the methodology of embodiments of the present invention, different thermoplastic materials may be tested against different cleaners or disinfectants to provide a uniform basis for comparison. This allows those who make chemicals, polymers and medical equipment to have a uniform way of evaluating those materials for compatibility with various cleaners and disinfectants used in the medical industry to make objective comparisons, and to allow end users to make the same evaluations and comparisons.

A test result of a tensile test and a measurement result of a natural frequency are easily associated with each other. A high-speed tensile testing machine 1 is a tensile testing machine that executes a tensile test by applying a test force F to a test target TP. The machine includes: a determination unit 513 that determines a timing at which a striking force FD is applied to a testing machine body 2; a striking structure 60 that applies the striking force FD to the testing machine body 2 at the timing determined by the determination unit 513; a first detection unit 514 that detects a vibration of the testing machine body 2 generated by the striking force FD; a calculation unit 515 that calculates a natural frequency FA of the high-speed tensile testing machine 1 on the basis of a detection result of the first detection unit 514; an execution instruction unit 516 that executes the tensile test; and a recording unit 517 that writes, in a result storage unit 518, information indicating a test result of the tensile test in association with information indicating the natural frequency FA. The timing is included in either before or after the tensile testing machine 1 executes the tensile test.

A method for acoustically measuring material properties of a test piece at high temperatures, includes the steps of: heating the test piece to within a testing temperature range; performing a background measurement within said testing temperature range by capturing a vibrational signal from the test piece within a calibration period, thereby obtaining a noise signal; performing an acoustic measurement on said test piece within said testing temperature range and within a testing period by: imparting a vibrational excitation onto the test piece; capturing a vibrational signal of the test piece within the testing period, thereby obtaining a vibrational response signal to said vibrational excitation, and obtaining the material properties of the test piece by analyzing the vibrational response signal, thereby taking into account the noise signal. A system is provided for acoustically measuring material properties of a test piece at high temperatures.

A system provided herein may be configured to evaluate helmet performance. The system may include an impact assembly that includes a stationary post operably coupled to one or more stationary load cells and a plurality of modular headforms. Each modular headform may include a first side and a second side configured to lock together around the impact assembly and receive a helmet. The modular headform may determine a position of the helmet relative to the one or more stationary load cells. Furthermore, the one or more stationary load cells may be configured to measure impact force at a position where one of the plurality of the modular headforms are operably coupled to the impact assembly. Additionally, each of the plurality of modular headforms correspond to a position in relation to the impact assembly to measure the impact force to the one or more load cells at a predefined number of impact locations on the helmet to evaluate the performance of the helmet.

A tester for evaluating pullout load capacity and bond quality of anchor bolts embedded in concrete includes a Schmidt hammer for measuring a rebound number and an ultrasonic pulse velocity tester for measuring the transit time of a pulse transmitted through concrete surrounding an anchor bolt. The rebound number and the transit time are combined and matched against a database record which identifies the pullout load capacity and the bond quality. The transit time is matched to thresholds of transit times associated with porosity, internal cracking, air voids, and water pockets located around the embedded anchor bolt. The Schmidt hammer is further modified by the incorporation of a digital level for measuring the vertical and horizontal angles of inclination of the plunger with the concrete surface, a guide tube for supporting the plunger, and by using a convex plunger tip for improved registration with anchor bolt head.

A tester for evaluating pullout load capacity and bond quality of anchor bolts embedded in concrete includes a Schmidt hammer for measuring a rebound number and an ultrasonic pulse velocity tester for measuring the transit time of a pulse transmitted through concrete surrounding an anchor bolt. The rebound number and the transit time are combined and matched against a database record which identifies the pullout load capacity and the bond quality. The transit time is matched to thresholds of transit times associated with porosity, internal cracking, air voids, and water pockets located around the embedded anchor bolt. The Schmidt hammer is further modified by the incorporation of a digital level for measuring the vertical and horizontal angles of inclination of the plunger with the concrete surface, a guide tube for supporting the plunger, and by using a convex plunger tip for improved registration with anchor bolt head.

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 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.

Test apparatus and methods for impact testing specimens, including edge impact testing are disclosed. The apparatus and methods disclosed include a pendulum and a bob which are used to impact test specimens against an impacting object.