An investigation of balsa wood over a range of strain-rates and impact velocities

An experimental investigation of the mechanical properties of balsa wood under quasi-static and dynamic conditions is presented. Cylindrical balsa wood specimens were compressed quasi-statically and dynamically along their three principal axes. Split Hopkinson Pressure Bar (SHPB) tests were carried out to determine the importance of the material strain-rate. Balsa wood is a relatively low strength material of about 1.5 MPa in the weakest direction, depending on density. Consequently, the SHPB tests were carried out using low mechanical impedance Polymethylmethacrylate pressure bars. Tests at high strain-rates resulted in an increase in both initial crushing and plateau stresses. Direct impact (DI) tests were performed to measure both the proximal and distal end forces over a range of impact velocities. These results both reinforce the SHPB data and provide measurements for stress enhancement