Steel structures subject to dynamic loads are prior to generate excessive vibration and noise. Viscoelastic treatment is an effective measure to mitigate the vibration and noise from thin-walled structures in a broad frequency range. H-shaped steel beams are widely used in civil engineering. So an experiment system is established and a series of impact hammer tests are conducted to assess the modal parameters, dynamic response and acoustic behaviour of an H-shaped steel beam coated with various viscoelastic treatments. Firstly, the spectra of the velocity response and acoustic radiation of the bare beam are analysed based on the tested data. Secondly, the resonance frequencies and modal loss factors of the beam with various viscoelastic treatments derived from the frequency response function are compared. Finally, the effect of the layout and thickness of viscoelastic patches on the mitigation of vibration and noise is discussed experimentally. It is shown that the modal loss factor of the first mode increases from 0.012 to 0.191 when the web is treated with 5 mm thick constrained layer damping (CLD). The viscoelastic patches on the web of the H-shaped beam are more effective to control the vibration and noise of the beam than the patches on the flanges. The viscoelastic treatment has distinct effect on the reduction of structural vibration and noise owing to the different dominant frequencies of vibration and noise as well as the frequency-dependent radiation efficiency. The normal velocity level of the H-shaped beam with an 8 mm thick web can be reduced by more than 10 dB and the sound pressure level around the beam about 8 dB when the web is partially covered with the constrained layer damping composed of 2.0 mm thick damping layer and 3.0 mm thick constraining layer.

承受动态载荷的钢结构会产生过大的振动和噪音。粘弹性处理是减轻宽频率范围内薄壁结构的振动和噪声的有效措施。H型钢梁广泛用于土木工程。因此，建立了一个实验系统并进行了一系列冲击锤测试，以评估涂有各种粘弹性处理的H型钢梁的模态参数，动力响应和声学性能。首先，根据测试数据分析了裸射束的速度响应谱和声辐射谱。其次，比较了从频率响应函数得到的各种粘弹性处理的梁的共振频率和模态损耗因子。最后，实验讨论了粘弹性斑块的布局和厚度对减轻振动和噪声的影响。结果表明，采用5 mm厚约束层阻尼（CLD）处理纤维网时，第一模态的模态损耗因子从0.012增加到0.191。H型梁腹板上的粘弹性斑块比法兰上的斑块更有效地控制梁的振动和噪声。由于振动和噪声的主导频率不同以及频率依赖的辐射效率，粘弹性处理对减少结构振动和噪声具有明显的作用。