Modal analysis is a dynamic response-based experimental structural identification procedure widely used for condition assessment and structural health monitoring (SHM). Piezoelectric sensors are smart material-based dynamic strain sensors being progressively implemented in vibration-based monitoring techniques. However, these have been so far limited to preliminary investigations on 1D and 2D structures with regard to modal analysis. Strain modal analysis using piezoelectric sensors has so far utilized only lower bending modes for frequency and mode shape-based SHM. This paper aims to evaluate the piezoelectric sensors for modal response measurement, modal parameter identification, and structural health monitoring of 3D structures, especially using torsional modes. It reports a comparative experimental study between the piezoelectric sensors and the accelerometers for dynamic response measurement, modal parameter extraction and damage identification and localization. Experimental modal analysis using impact hammer-based excitation is performed on two lab-sized specimens under different boundary conditions. Displacement mode shapes from both the sensors are used to determine the location and the severity of the damage. Torsional and bending modes are studied distinctly for sensitivity towards damage monitoring. Modal assurance criteria (MAC), coordinated MAC (CoMAC), and modal strain energy (MSE) are adopted as damage indicators. Results of the study show that the piezoelectric sensors are equivalent to accelerometers for response measurements and modal parameter extraction. They possess enhanced sensitivity towards damage monitoring as compared to accelerometers. Torsional modes perform better than bending modes for damage localization and severity quantification. Bending modes from both sensors are ineffective in locating the damage precisely. Modal strain energy (MSE) based damage index from torsional modes acquired from piezoelectric sensor performs best in terms of sensitivity towards damage location and exhibits peak severity, especially for incipient damage. The study establishes piezoelectric sensors as reliable and cost-effective modal response sensors.

模态分析是一种基于动态响应的实验性结构鉴定程序，广泛用于状态评估和结构健康监测（SHM）。压电传感器是基于智能材料的动态应变传感器，已在基于振动的监视技术中逐步实现。但是，到目前为止，这些方法仅限于关于模态分析的1D和2D结构的初步研究。迄今为止，使用压电传感器进行的应变模态分析仅针对基于频率和模式形状的SHM使用了较低的弯曲模式。本文旨在评估用于3D结构的模态响应测量，模态参数识别和结构健康监测的压电传感器，尤其是使用扭转模式的压电传感器。它报告了在压电传感器和加速度计之间进行动态响应测量，模态参数提取以及损伤识别和定位的对比实验研究。使用基于冲击锤的激励的实验模态分析是在不同边界条件下对两个实验室规模的样本进行的。来自两个传感器的位移模式形状用于确定损坏的位置和严重程度。对扭转和弯曲模式进行了专门研究，以提高其对损伤监测的敏感性。模态保证标准（MAC），协调MAC（CoMAC）和模态应变能（MSE）被用作损伤指标。研究结果表明，压电传感器等效于加速度计，用于响应测量和模态参数提取。与加速度计相比，它们对损坏监测的灵敏度更高。在损伤定位和严重性量化方面，扭转模式的性能优于弯曲模式。两个传感器的弯曲模式都无法有效地准确定位损坏位置。从模态能量（MSE）获得的基于来自压电传感器的扭转模式的损伤指数在对损伤位置的敏感性方面表现最佳，并且表现出峰值严重性，尤其是对于初期损伤。该研究将压电传感器确定为可靠且经济高效的模态响应传感器。从模态能量（MSE）获得的基于来自压电传感器的扭转模式的损伤指数在对损伤位置的敏感性方面表现最佳，并且表现出峰值严重性，尤其是对于初期损伤。该研究将压电传感器确定为可靠且经济高效的模态响应传感器。从模态能量（MSE）获得的基于来自压电传感器的扭转模式的损伤指数在对损伤位置的敏感性方面表现最佳，并且表现出峰值严重性，尤其是对于初期损伤。该研究将压电传感器确定为可靠且经济高效的模态响应传感器。