This paper presents the time history response of a sandwich beam with a porous core subjected to two moving harmonic loads with opposite directions. In the modelling, the beam is combined of two isotropic face sheets and a porous core with symmetric porosity distribution. The quasi-3D shear deformation beam theory in conjunction with Hamilton’s variational principle is utilized to set up the governing equations of motion. The Navier solution is used to obtain the displacement field. | Vietnam Journal of Mechanics Vol. 46 No. 1 2024 pp. 44 57 DOI https 0866-7136 20580 DYNAMIC RESPONSE OF SANDWICH BEAM WITH POROUS CORE EXCITED BY TWO HARMONIC LOADS TRAVELLING IN OPPOSITE DIRECTIONS Tran Quang Hung1 Do Minh Duc 1 Tran Minh Tu2 1 The University of Da Nang - University of Science and Technology Da Nang Vietnam 2 Hanoi University of Civil Engineering Hanoi Vietnam E-mail ducdhbk@ Received 23 January 2024 Revised 02 March 2024 Accepted 12 March 2024 Published online 31 March 2024 Abstract. This paper presents the time history response of a sandwich beam with a porous core subjected to two moving harmonic loads with opposite directions. In the modelling the beam is combined of two isotropic face sheets and a porous core with symmetric poros- ity distribution. The quasi-3D shear deformation beam theory in conjunction with Hamil- ton s variational principle is utilized to set up the governing equations of motion. The Navier solution is used to obtain the displacement field. The accuracy of the study is val- idated by comparing with existing results in the literature for specific cases. Effects of the velocity and excitation frequency of the moving loads on the deflection-time history are investigated and discussed. Numerical results reveal that in the case of the double- moving harmonic loads in the antiphase the resonance phenomenon cannot occur when the excitation frequency approaches the natural frequency of the beam. Keywords sandwich porous beam moving harmonic load Navier solution dynamic re- sponse. 1. INTRODUCTION Lightweight sandwich structures with a porous core offer unique potential for var- ious applications in space aerospace automotive defense and civil engineering 1 . In these structures the porous core plays a prime key since it has many advantages such as high energy absorption ability high resistance to impact high strength- and stiffness- to-weight ratios 2 3 . Consequently this type of structure has gained .
