Abstract: The present invention discloses a non-contact dynamic strain field measuring method and system for a rotating blade. The method includes the following steps: establishing a three-dimensional finite element model of a to-be-measured rotating blade, and extracting modal parameters of the three-dimensional finite element model; determining the number and axial mounting positions of blade tip timing sensors; constructing a conversion matrix of finite measuring point displacement and an overall strain field; and acquiring blade tip finite position displacement of the rotating blade based on the blade tip timing sensors, and acquiring, by a dynamic strain, dynamic strains of the rotating blade at any moment, on any position and in any direction based on modal processing of the conversion matrix.

Abstract: The present disclosure discloses a method for detecting a natural frequency of a blade by a single blade tip timing sensor. In the method, two segments of displacement data vectors are subjected to dot product to obtain a product data vector after multiplication of corresponding serial numbers, the product data vector is subjected to low-frequency filtering, the filtered product vector is subjected to Hilbert transform to obtain an instantaneous phase, the instantaneous phase is subjected to discrete Fourier transform, an absolute value of a natural frequency difference between blades is extracted from amplitude frequency data, blades on a bladed disk are subjected to permutation and combination to obtain absolute values of the natural frequency differences between all the blades, a sum of the absolute values of the natural frequency differences between each blade and other blades is calculated.

Abstract: The present disclosure relates to the technical field of metal materials, and more specifically, to a non-heat treated aluminum alloy stress-bearing member material with high toughness and high casting performance and its preparation method. The non-heat treated aluminum alloy stress-bearing member material with high toughness and high casting performance includes the following components in terms of mass percentage: Si: 8.5-12.0%, Mg: 0.10-0.35%, Mn: 0.25-0.4%, Cr: 0.02-0.14%, V: 0.02-0.38%, Sr: 0.01-0.04%, Ti: 0.05-0.11%, B?0.005%, Ca?0.05%, Zr?0.1%, Zn?0.1%, RE?0.1%. The total amount of other impurities is less than or equal to 0.25%, and the balance is Al. Under the premise of ensuring that the alloy has good die casting performance, the die-casting parts in non-heat-treated state can have excellent comprehensive mechanical properties, thereby meeting the performance requirements of the die casting stress-bearing member.

Abstract: In some examples, a PowerPoint slide is created that, when presented at a first location, will provide an animation that has been obtained during the presentation from a second location through the Internet. Creating the slide includes insertion an active object in the slide, the active object enabling a call to the multimedia content at the second location. The animation is expressed in Flash format, and the slide, when presented, includes interactive features for controlling the animation.