Dissertation > Excellent graduate degree dissertation topics show

Research of Mechanical-properties Damage Effect on Fused Silica

Author: ChenQingHong
Tutor: XuShiZhen; JiangXiaoDong
School: University of Electronic Science and Technology
Course: Condensed Matter Physics
Keywords: fused silica pre-stress hardness damage threshold damage growth threshold
CLC: TN249
Type: Master's thesis
Year: 2013
Downloads: 8
Quote: 0
Read: Download Dissertation

Abstract


In building the high power laser system, the load capacity is one of the mainproblems that must be considered, since it is the ultimate limitation for the outputcapacity of the laser system.Therefore, the research on the anti-laser damage capacity of optical element hasalways been the hot-spot in the field of high power laser system. In return, everyprogress in the anti-laser damage capacity will always result in the leap in the outputcapacity of the laser system.The fused silica has been comprehensively used in the high power laser system, forthis superiority in optical performance and anti-radiation capacity. Lots of people haveconducted a plenty of theoretical and experimental researches, but very few of themhave concerned the impact of the mechanical specifics on the anti-radiation capacity ofthe fused silicaIn fact, nowadays the main stream methods to increase the anti-radiation capacityof the fused silica have more or less to be connected with the change in the mechanicalspecifics, such as HF surface etching, which deactivate the micro-crack and avoid thestress concentration, therefore increase the anti-tension capacity of the fused silica; CO2laser maintainance, which is the thermal treatment to the initial damage point, changethe stress distribution around the damage point and hence raise the mechanicalperformance around it.This paper has dealt with the impact of the mechanical specifics (the surfacestrength and hardness of the fused silica) on the anti-radiation capacity of the fusedsilica. The surface strength can be varied by apply a uniform stress layer on the surfaceof the fused silica to raise the anti-tension capacity.Meanwhile, hardness is one of themechanical performances of the fused silica.Main body：1. The code simulation shows that when the boundary of the fused silica underexternal constraint, the stress in a certain point in the surface of the fused silicaincreases with the deformation of the center point. If the deformation of the center point remains constant, the stress in the circular ring also remains constant and it decreasesaccording to the distance from the center.2. The damage threshold and the damage growth threshold are measured underdifferent surface stress states by applying external forces to the fused silica. And it isfound the damage threshold can be raised by the proper uniform distributed stress, butthe damage growth threshold will be lowered under this condition. Excessive stress willlower the damage threshold for worsening the surface mechanical performance. Surfacetension is bad to increase the damage threshold.3. The fused silica of the same specifications from different manufacturers havebeen tested by pressing in method. The triple frequency laser damage experiments arecarried out under different hardness. The conclusions are: the damage threshold varieslinearly with the hardness in a certian range and it tends to be saturated when thehardness reach a certain value.

Related Dissertations

  1. Synthesis and Application of the chloro- methoxy fatty acid methyl esters,TQ414.8
  2. Stability of Polymer Monomer Bpa, 1,4-BD, TPA in Super/sub-critical Water,O631.3
  3. Research on the Test of Weak Equivalence Principle with a High-Q Torsion Balance,O412
  4. Research on a Novel Combined Fused Silica Cylinder Shell Vibrating Gyroscope,TH703
  5. Fe ( 3 ) ions on the performance impact of KDP crystal,O734
  6. Of TiC Reinforced relative Mo alloy mechanical properties and microstructure,TG146.412
  7. FDTD Analysis on Influence of Micro-Nano Surface on Near-Field Light Intensity Distribution in KDP Crystal,TG665
  8. Evaluation Method of the Prestressed Concrete Bridge Service Performance Based on the Section Stress Status,U441.5
  9. Research on the Welding Procedure and Microstructure and Mechanical Property of Tubular Aluminum Busbar,TG457.14
  10. Study of Mechanism Using Two-Direction Pre-Stress to Control Welding Distortion and Hot Cracking,TG404
  11. Reaserch on the Long-Term Creep Deflection of Prestressing Concrete Continuous Rigid Frame Bridges,U448.23
  12. Construction of Wheat Transformation Vector of Gene Determining Grain Hardness for RNA Interference,S512.1
  13. Designing of the Measurement and Control System of the Burinell Hardness Test Machine Base on Embedded and Picture Identify Technology,TH871.5
  14. Research on Nanocomposition Ti-Si-N Thin Films Prepared by Magnetron Sputtering,O484.1
  15. Simulation Approach to Middling and Small Span Bridge Based on Detected Effective Prestressed,U446
  16. Research on the Key Processing Factors That Influence the Machining of the Fused Silica with Reactive Atmospheric Pressure Plasma,TG664
  17. Research on Shrinkage and Creep Effect for High-Pier & Long-Span Continuous Rigid-Frame Bridges,U441.5
  18. Study on the Application of Overall Cast-in-situ Prestressed Anchorge Sheet Pile Retaining Wall,U417.1
  19. Construction Control and Stress Analysis in the Forming of Continues T-frame Bridge,U448.23
  20. Three Prestressed Continuous Beam Bridge System Cantilever Construction Control Technology,U445.57
  21. Research on Mechanical Behaviors of Unbonded Prestressed Concrete-Filled Square Steel Tubular Structures,TU398.9

CLC: > Industrial Technology > Radio electronics, telecommunications technology > Photonics technology,laser technology > Laser technology, the maser > Laser applications
© 2012 www.DissertationTopic.Net  Mobile