Cantilever square plate torsional vibration method for testing wood shear modulus

The invention provides a cantilever square plate torsional vibration method for testing wood shear modulus. A formula for testing the principal shear modulus of the wood and a corresponding vibration mode coefficient formula are given according to the energy principle and regression analysis; the method adopts a cantilever square plate as a test piece, has the advantages of simplicity and convenience in operation and high test precision, effectively reveals the numerical difference of the shear moduli in two mutually vertical directions on the principal plane of the wood, and is superior to other dynamic methods for testing the shear moduli of the wood; the method is suitable for a cantilever square plate test piece with the width-to-thickness ratio of 6-30 (or 9-25) to test wood LT, LR and RT direction shear moduli and TL direction shear moduli (shown in the vibration mode coefficients C1 and C2 formulas and the formula (10) of the formulas (2) to (9)), and when the width-to-thickness ratio is 15, the test v