空心与聚氨酯泡沫填充节点耗能性能研究

发布时间：2023-04-02 08:27

　　对于重要建筑结构,其遭受爆炸冲击相关的威胁与日俱增,因此,它们的安全性已成为目前研究的一个热点。国内外学者一直致力于吸能结构的研究,用以保护建筑物免受爆炸荷载作用。尽管一些学者开展了针对结构抗爆的研究,但对于可放置在抗爆幕墙和结构承重构件之间的能量吸收节点的研究相对较少。在本文研究中,提出了能够吸收爆炸能量并减小可传递到承载构件峰值力的能量吸收节点。这些空心或聚氨酯泡沫填充的能量吸收节点具有先进的几何形状。除了用于能量吸收之外,本文所提出的吸能构件还可应用到车辆碰撞中以提高车辆的耐撞性,并可有效提高乘客的安全性。首先,对节点开展准静态压缩试验。利用显式有限元程序LS-DYNA建立节点准静态压缩的数值模型。然后,开展针对节点的动态压缩试验研究。同样,利用LS-DYNA程序建立模拟节点动态压缩的数值模型。针对两种压缩情况,评估所设计节点的失效机理和能量吸收性能。结果表明,填充聚氨酯泡沫,增加折板的厚度,降低从折板顶部到折板弯折点的高度,可以改善节点的能量吸收性能。通过准静态和动态压缩的比较可以得出结论,动态压缩(最大冲击速度为13m/s)具有与准静态压缩相似的失效机制,但具有较高的能量吸收...

【文章页数】：85 页

【学位级别】：硕士

【文章目录】：
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
结论
Conclusions
Limitations of the study
References
List of publications
Acknowledgement
Resume



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