【正文】 關(guān)鍵詞 ：激光沖擊處理，疲勞壽命，數(shù)值模擬，殘余應力場，疲勞斷口，鋁 合金小孔 安徽工業(yè)大學 畢業(yè)設計（論文）說明書 3 ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ 裝 ┊ ┊ ┊ ┊ ┊ 訂 ┊ ┊ ┊ ┊ ┊ 線 ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ABSTRACT Laser shock modification and lifeextending technology is the use of the laser beam highly concentrated in the direction and energy as a tool for surface modification or extension of the material. The technology makes the prehensive use of modern physics .chemistry .puter. Materials science .advanced manufacturing technology and other aspects of Results or knowledge .and it has a significant impact on ponent selection .design manufacturing. Aluminum alloy holes are the typical locations of stress concentration which easily generate fatigue cracks under cyclic loading and yield fatigue rupture .so this text use the laser shock technology .through the parative analysis .the better process of LSP before holedrilling was adopted to study the residual stress field of fastener holes at different parameters and its fatigue property by the methods of experiments and simulations, and fatigue fracture were analyzed. The research process is as following :based on the FEM code ABAQUS ,the general idea of Numerical simulation to strengthen holes was set .by the LSP parameters was analyzed ,and then presented the optimizing region of LSP parameters .Then ,selected the power density ,pulse width ,spot diameter and shot numbers as the research object ,without considering the interaction between the shock parameters ,the effect of laser shock parameters on the residual stress field were studied. Then observation the fatigue fracture indicated the strength of antifatigue properties .Finally ,through the simulation we can study the residual stress field of specimens before and after holedrilling and the fatigue properties of specimens before and after LSP .Then we can get the point of the effect of treatment on the fatigue life of spot overlapping KEY WORDS :Laser shock processing。 Residual stress field。 Aluminum alloy 安徽工業(yè)大學 畢業(yè)設計（論文）說明書 4 ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ 裝 ┊ ┊ ┊ ┊ ┊ 訂 ┊ ┊ ┊ ┊ ┊ 線 ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ 目錄 第一章 緒論 .................................................................................................................... 1 前言 ................................................................................................................... 1 小孔技術(shù)強化的傳統(tǒng)工藝 .................................................................................... 2 冷擠壓技術(shù) ............................................................................................... 2 機械噴丸技術(shù) ............................................................................................ 3 激光沖擊技術(shù) ..................................................................................................... 4 激光沖擊強化的原理 ................................................................................. 4 激光沖擊強化的特點 ................................................................................. 5 激光沖擊強化的效應 ................................................................................. 5 激光沖擊強化的影響因素 .................................................................................... 8 激光參數(shù) ................................................................................................... 8 能量吸收層和約束層 ................................................................................. 8 材料 .......................................................................................................... 9 常見激光沖擊工藝 .............................................................................................. 9 激光沖擊強化技術(shù)的研究與應用 ....................................................................... 15 第二章 激光沖擊小孔的數(shù)值建模 ................................................................................... 18 數(shù)值模擬的總體思路 ......................................................................................... 18 ABAQUS 建模過程 ............................................................................................ 18 幾何模型的建立 ...................................................................................... 19 材料的本構(gòu)模型 ..................................................................................... 19 網(wǎng)格劃分 ................................................................................................. 20 載荷模塊 ................................................................................................. 20 邊界條件的設置 ....................................................................................... 18 ABAQUS 中分析步模塊 ............................................................................ 19 本章小結(jié) .......................................................................................................... 25 第三章 激光沖擊過程中應力場的數(shù)值模擬 ..................................................................... 26 激光沖擊處理工藝參數(shù)的選擇 ........................................................................... 26 激光脈沖功率密度的選擇 ........................................................................ 26 光斑直徑的選擇 ...................................................................................... 27 激光脈沖寬度的選擇 ............................................................................... 28 激光沖擊過程中的動態(tài)分析 ............................................................................... 28 動態(tài)導入靜態(tài) ................................................................................................... 30 本章小結(jié) ............................