對(duì)于重要建筑結(jié)構(gòu),其遭受爆炸沖擊相關(guān)的威脅與日俱增,因此,它們的安全性已成為目前研究的一個(gè)熱點(diǎn)。國(guó)內(nèi)外學(xué)者一直致力于吸能結(jié)構(gòu)的研究,用以保護(hù)建筑物免受爆炸荷載作用。盡管一些學(xué)者開(kāi)展了針對(duì)結(jié)構(gòu)抗爆的研究,但對(duì)于可放置在抗爆幕墻和結(jié)構(gòu)承重構(gòu)件之間的能量吸收節(jié)點(diǎn)的研究相對(duì)較少。在本文研究中,提出了能夠吸收爆炸能量并減小可傳遞到承載構(gòu)件峰值力的能量吸收節(jié)點(diǎn)。這些空心或聚氨酯泡沫填充的能量吸收節(jié)點(diǎn)具有先進(jìn)的幾何形狀。除了用于能量吸收之外,本文所提出的吸能構(gòu)件還可應(yīng)用到車(chē)輛碰撞中以提高車(chē)輛的耐撞性,并可有效提高乘客的安全性。首先,對(duì)節(jié)點(diǎn)開(kāi)展準(zhǔn)靜態(tài)壓縮試驗(yàn)。利用顯式有限元程序LS-DYNA建立節(jié)點(diǎn)準(zhǔn)靜態(tài)壓縮的數(shù)值模型。然后,開(kāi)展針對(duì)節(jié)點(diǎn)的動(dòng)態(tài)壓縮試驗(yàn)研究。同樣,利用LS-DYNA程序建立模擬節(jié)點(diǎn)動(dòng)態(tài)壓縮的數(shù)值模型。針對(duì)兩種壓縮情況,評(píng)估所設(shè)計(jì)節(jié)點(diǎn)的失效機(jī)理和能量吸收性能。結(jié)果表明,填充聚氨酯泡沫,增加折板的厚度,降低從折板頂部到折板彎折點(diǎn)的高度,可以改善節(jié)點(diǎn)的能量吸收性能。通過(guò)準(zhǔn)靜態(tài)和動(dòng)態(tài)壓縮的比較可以得出結(jié)論,動(dòng)態(tài)壓縮(最大沖擊速度為13m/s)具有與準(zhǔn)靜態(tài)壓縮相似的失效機(jī)制,但具有較高的能量吸收...

【文章頁(yè)數(shù)】：85 頁(yè)

【學(xué)位級(jí)別】：碩士

【文章目錄】：
摘要
Abstract (In English)
Notations
Chapter 1 Introduction
    1.1 Background
    1.2 Literature review
        1.2.1 Traditional thin-walled empty energy absorption structures
        1.2.2 Geometric modification of the traditional thin-walled empty structures
        1.2.3 Foam-filled energy absorption structures
        1.2.4 Effects of the foam density
    1.3 Energy absorption parameters
    1.4 Aim and Objectives
Chapter 2 Mechanical properties of the materials
    2.1 Introduction
    2.2 Tensile test of mild steel samples
    2.3 Compression test of polyurethane foam samples
    2.4 Summary
Chapter 3 Quasi-static compression of the connectors
    3.1 Introduction
    3.2 Test specimens
    3.3 Experimental study
    3.4 Calculation of the energy absorption parameters
    3.5 Numerical study
        3.5.1 Model description
        3.5.2 Element formation and mesh-optimization
        3.5.3 Boundary, contact and quasi-static load conditions
        3.5.4 Material properties
        3.5.5 Validation of the numerical results
    3.6 Results and discussions
        3.6.1 Failure mechanism
        3.6.2 Force-displacement curves
        3.6.3 Effects of the polyurethane foam
        3.6.4 Effects of thickness of the armed plates
        3.6.5 Effects of the height ht
    3.7 Summary
Chapter 4 Dynamic compression of the connectors
    4.1 Introduction
    4.2 Test specimens
    4.3 Numerical study
        4.3.1 Model description
        4.3.2 Element formation and mesh-optimization
        4.3.3 Boundary, contact and dynamic load conditions
        4.3.4 Material properties
    4.4 Experimental study
    4.5 Calculation of the energy absorption parameters
    4.6 Validation of the numerical results
    4.7 Results and discussions
        4.7.1 Failure mechanism and force-displacement curves
        4.7.2 Effects of the polyurethane foam
        4.7.3 Effects of the height ht
        4.7.4 Comparison with the quasi-static compression
    4.8 Summary
結(jié)論
Conclusions
Limitations of the study
References
List of publications
Acknowledgement
Resume



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