A RECTANGULAR ELEMENT OF THIN PLATES BASED UPON THE GENERALIZED VARIATIONAL PRINCIPLES

Based on generalized variational principles, an element called MR-12 was constructed for the static and dynamic analysis of thin plates with orthogonal anisotropy. Numerical results showed that this incompatible element converges very rapidly and has good accuracy. It was demonstrated that generalized varialional principles arc useful and effective in founding incompatible clement.Moreover, element MR-12 is easy for implementation since it does not differ very much from the common rectangular element R-12 of thin plate.

High-Efficiency Generation of 0.12 mJ, 8.6 Fs Pulses at 400 nm Based on Spectral Broadening in Solid Thin Plates

We demonstrate eftlcient generation of continuous spectrum centered at 40Ohm from solid thin plates. By frequency doubling of 0.8m J, 3Ors Ti：sapphire laser pulses with a BBO crystal, 0.2m J, 33fs laser pulses at 400nm are generated. Focusing the 400-nm pulses into 7 thin fused silica plates, we obtain 0.15mJ continuous spectrum covering 350-450 nm. After compressing by 3 pairs of chirped mirrors, 0. 12 m J, 8.6 fs pulses are achieved. To the best of our knowledge, this is the first time that sub-10-fs pulses centered at 400nm are generated by solid thin plates, which shows that spectral broadening in solid-state materials works not only at 800nm but also at different wavelengths.

Study on the influence of base plate deformation on long undulators

Background Nineteen undulators of various types are being fabricated for high-energy photon source(HEPS).In order to ensure the optical performance of the undulators,the girder deformation is usually carefully optimized during the structural design stage.Purpose Optimization of magnet girder deformation is one of the key points to ensure undulator magneticfield performance.To reduce magnet girder deformation,base plate,feet and strong back should be designed carefully.In the HEPS undulator design and manufacturing stage,it is found that under special circumstances,such as after the height of the feet is adjusted,or after the undulator is lifted to other place,the base plate and girder may deform more than expected.Methods Therefore based on ANSYS simulation and experimental test results,the factors causing the deformation of the girders are carefully analyzed.Base plate and feet were optimized for different types of undulators to avoid girder deformation.Related simulation and laser tracker measurement were performed tofind out the reason in this paper.Results and conclusion Results show that the base plate of C-frame undulators will collapse and deform under the action of magnetic force.Asymmetric sagged base plate is the main reason of girder deformation.Increasing the thickness of the base plate and increasing the number of feet can both reduce that deformation.Optimization of magnet girder deformation is one of the key points to ensure undulator magneticfield performance.To reduce magnet girder deformation,base plate,feet and strong back should be designed carefully.

MEMS gyro temperature compensation identification algorithm based on thin plate spline interpolation method

MEMS gyroscopes are widely used in the underwater vehicles owing to their excellent performance and affordable costs.However,the temperature sensitivity of the sensor seriously affects measurement accuracy.Therefore,it is significantly to accurately identify the temperature compensation model in this paper,the calibration parameters were first extracted by using the fast calibration algorithm based on the Persistent Excitation Signal Criterion,and then,MEMS gyro temperature compensation model was established by utilizing the thin plate spline interpolation method,and the corresponding identification results were compared with the results from the polynomial fitting method.The effectiveness of the proposed algorithm has been validated through the comparative experiment.