Elimination of accelerometer mass loading effects in sparse identification of impact forces.

• Novel method is proposed for eliminating mass loading effect during impact force identification. • Proposed method introduces pseudo-forces to re-express accelerometer mass loading effects. • Proposed method can simultaneously identify impact force and accelerometer masses. • Application of proposed sparse regularization-based method is effective and robust. Identifying impact force from measured structural responses has been extensively studied. Contact sensors such as accelerometers are often applied for recording the structural responses. Masses of the contact sensors would change the structural dynamic properties, especially for lightweight structures. To eliminate the effects of additional masses in force identification, this paper proposes a novel method for reconstructing the impact force. The proposed method is developed from existing sparse regularization-based method. In the process of forward analysis, a key step is to introduce some pseudo-forces for simulation of the additional mass loading effects. The measured responses are regarded as the sum of two components. One is induced by the impact force, and the other one is caused via pseudo-forces. In the process of inverse analysis, impact force identification involving notable sensor mass is treated as a problem of multi-force identification, in which both impact force and pseudo-forces are simultaneously identified. The impact force is identified via sparse regularization which determines more accurate results insensitive to noise. Masses of installed sensors are estimated from the identified pseudo-forces because the pseudo-forces are a translated expression of mass loading effects. Therefore, the effects of additional masses can be eliminated in force identification. Numerical simulations and experimental studies on a cantilever beam are carried out. Cases studies show that the proposed method can be applied for estimating the impact force and additional masses with high accuracy and strong robustness. Some related issues are discussed as well. [ABSTRACT FROM AUTHOR]