Abstract

Due to its importance in the construction of ships, wood was one of the first substances to have the velocity dependence of its resistance to impact quantified. This was achieved in England and France early in the 19th century. Techniques for measuring the high-rate mechanical properties of wood were developed around the start of the 20th century. These studies involved drop-weight and pendulum machines to quantify the dynamic fracture toughness of timbers and were mostly performed by the US Forestry Service. It was not until 1977 that the first high-rate compression stress-strain curves of wood were obtained using the Kolsky bar, despite this device having been developed in Britain in the 1940s. It took until the mid-1990s and the desire to use wood to cushion the drop-impact of vessels used to transport dangerous waste that Kolsky bar studies of wood began in earnest in Britain, the Czech Republic and Russia. Even so, to date fewer than 100 such studies have been published compared to nearly 5,000 for metals. The seminar will summarize the effects of anisotropy, stress state, multiple repeat loading, moisture content, temperature, and density on the high-rate properties of a wide range of woods. The seminar will finish with suggestions for what needs doing in the future. A review paper on this topic has recently been published in ‘Journal of Dynamic Behavior of Materials’.