A harmless thin film elastic modulus measurement method through bending the nonlinear sliding cantilever beam

•Based on nonlinear Euler-Bernoulli beam theory, the elastic modulus test method of specimens is established.•The measurement precision can meet the engineering requirements when the large displacement takes place.•The flexible sensor which cannot bear large tensile stress can be tested with proposed method.•The error and sliding effect is discussed with tensile experimental data in the paper. This paper presents the design of a novel elastic modulus measurement method through bending the specimen to estimate the elastic modulus of a small irregular thin-film specimen without causing damage. First of all, based on nonlinear Euler-Bernoulli beam theory, A measurement system is constructed with a laser displacement sensor and a dynamometer to obtain a relationship between deflection and force. The elastic modulus is estimated by the strain energy and the work of a constant force. Secondly, uniaxial tensile tests of specimens are conducted to evaluate the accuracy of the proposed method. The experimental results show good agreement between the elastic modulus obtained using the proposed method and the elastic module obtained through tensile test method. The relative error between them is less than 2.0%, which validates the proposed method’s performance on accuracy. To sum up, the proposed test method is a supplement to the harmless elastic modulus measurement method.