GyroWheel is an innovative device that combines the actuating capabilities of a control moment gyro with the rate sensing capabilities of a tuned rotor gyro by using a spinning flex-gimbal system. However, in the process of the ground test, the existence of aerodynamic disturbance is inevitable, which hinders the improvement of the specification performance and control accuracy. A vacuum tank test is a possible candidate but is sometimes unrealistic due to the substantial increase in costs and complexity involved. In this paper, the aerodynamic drag problem with respect to the 3-DOF flex-gimbal GyroWheel system is investigated by simulation analysis and experimental verification. Concretely, the angular momentum envelope property of the spinning rotor system is studied and its integral dynamical model is deduced based on the physical configuration of the GyroWheel system with an appropriately defined coordinate system. In the sequel, the fluid numerical model is established and the model geometries are checked with FLUENT software. According to the diversity and time-varying properties of the rotor motions in three-dimensions, the airflow field around the GyroWheel rotor is analyzed by simulation with respect to its varying angular velocity and tilt angle. The IPC-based experimental platform is introduced, and the properties of aerodynamic drag in the ground test condition are obtained through comparing the simulation with experimental results. Full article

This paper presents a simple methodology to perform a high temperature coupled thermo-mechanical test using ultra-high temperature ceramic material specimens (UHTCs), which are equipped with chemical composition gratings sensors (CCGs). The methodology also considers the presence of coupled loading within the response provided by the CCG sensors. The theoretical strain of the UHTCs specimens calculated with this technique shows a maximum relative error of 2.15% between the analytical and experimental data. To further verify the validity of the results from the tests, a Finite Element (FE) model has been developed to simulate the temperature, stress and strain fields within the UHTC structure equipped with the CCG. The results show that the compressive stress exceeds the material strength at the bonding area, and this originates a failure by fracture of the supporting structure in the hot environment. The results related to the strain fields show that the relative error with the experimental data decrease with an increase of temperature. The relative error is less than 15% when the temperature is higher than 200 °C, and only 6.71% at 695 °C. Full article

Five measurements of claw conformation (toe angle, claw height, claw width, toe length and abaxial groove length) taken directly from the hoof were compared with the measurements taken from digital images of the same claws. Concordance correlation coefficients and limits-of-agreement analysis showed that, for four of the five measures (claw height, claw width, toe length and abaxial groove length), agreement was too poor for digital and manual measures to be used interchangeably. For all four of these measures, Liao’s modified concordance correlation coefficient (mCCC) was ≤0.4, indicating poor concordance despite Pearson’s correlation being >0.6 in all cases. The worst concordance was seen for toe length (mCCC = 0.13). Limits-of-agreement analysis showed that, for all four measures, there was a large variation in the difference between the manual and digital methods, even when the effect of mean on difference was accounted for, with the 95% limits-of-agreement for the four measures being further away from the mean difference than 10% of the mean in all four cases. The only one of the five measures with an acceptable concordance between digital and manual measurement was toe angle (mCCC = 0.81). Nevertheless, the limits-of-agreement analysis showed that there was a systematic bias with, on average, the manual measure of toe angle, being 2.1° smaller than the digital. The 95% limits-of-agreement for toe angle were ±3.4°, probably at the upper limit of what is acceptable. However, the lack of data on the variability of individual measurements of claw conformation means that it is unclear how this variability compares to measurement of toe angle in the same animal using the same or a different manual technique. Full article