Browsing by Author "Ma, Y. Y."

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Bottle beam generation from a frequency-doubled Nd:YVO4 laser
(2018-11-08)
Tung, J. C.
;
Ma, Y. Y.
;
Miyamoto, K.
;
Chen, Y. F.
;
Omatsu, T.
We demonstrate, for the first time, the direct generation of a bottle beam with a well-isolated threedimensional zero-intensity dark core (high potential barrier) from a compact intracavity frequency-doubled Nd:YVO4 laser with a nearly hemispherical cavity. We also numerically calculate the physical properties of the generated bottle beam using a coherent superposition of a series of frequency-locked Laguerre-Gaussian modes.
Bottle beam generation from a frequency-doubled Nd:YVO4 laser with a tightly end-pumping geometry
(2018-01-01)
Tung, J. C.
;
Ma, Y. Y.
;
Chen, Y. F.
;
Miyamoto, K.
;
Omatsu, T.
We first demonstrated the generation of an optical bottle beam with a zero-intensity region surrounded by three-dimensional bright regions from an intra-cavity frequency-doubled Nd:YVO4 laser with a nearly hemispherical cavity configuration. We also numerically analyzed the components of the generated bottle beam which consists of a series of Laguerre-Gaussian modes. The experimental results can be excellently reconstructed with the theoretical model.
Direct generation of a 'bottle beam' from an end-pumped Nd:YVO4 laser with second-harmonic generation
(2018-01-01)
Tung, J. C.
;
Ma, Y. Y.
;
Chen, Y. F.
;
Huang, K. F.
;
Omatsu, T.
We have demonstrated, for the first time, the generation of an optical 'bottle beam' with a 'zero-intensity' region surrounded by three-dimensional bright regions from an intra-cavity frequency-doubled Nd:YVO4 laser with a nearly hemispherical cavity configuration.
Hysteretic behavior of bolt-column joints under in-plane loading combinations by experimental and numerical study
(2020-06-01)
Ma, H. H.
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Ma, Y. Y.
;
Yu, Z. W.
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Jiang, P.
;
Fan, F.
The bolt-column (BC) joint has enough bending stiffness satisfying large-span single-layer reticulated shell structure well. The hysteretic behavior of BC joints under different in-plane combinations of bending moment and axial force is investigated in this study. Firstly, precise finite element models (FEM) of the BC joints, which considered the material and the geometric and contact nonlinearities, were established in ABAQUS. The failure modes, hysteretic curves, skeleton curves, and bearing capacity for assessing the joint hysteretic behavior were investigated in detail by the numerical analysis. BC joints under different combined axial force and cyclic bending loads were studied by numerical analysis to obtain the impact of the axial force, which provides necessary technical support for engineering practice. Three tests were conducted and the results verified that the FEM was effective in simulating the joint behavior by comparison with the test results. The research shows that the hysteretic capacity of BC joints under in-plane bending is weaker than that under out-of-plane bending, but the bearing capacity of former is higher. Increasing the thickness of the side and middle plates can slightly enhance the joint in-plane hysteretic capacity, which is improved with small axial compression and reduced with high axial compression and axial tension.