Design and Experimental Study of Flexion StiffnessDesign and Experimental Study of Flexion Stiffness Testing Device for Alpine Ski-Boots Testing Device for Alpine Ski-Boots

Abstract Objectives: Currently, the accuracy of ski boot flexion stiffness measurement device is less than satisfactory, as the perpendicularity of loading direction to the dummy foot and the consistency of ski boot binding force cannot be guaranteed. Therefore, the overall aim is to design and build a testing device for the flexion stiffness of ski boots. Specifically, the objectives were to (i) provide a CAD design of key components of the flexion stiffness testing equipment with the support of finite element analysis. (ii) practically build the flexion stiffness testing equipment. (iii) to investigate the reliability of flexion stiffness test equipment and the effect of ski boot snap tightness. Design and method: Design L-shaped components in a way that guarantees the direction of the loading force remains perpendicular to the dummy foot loading bar while undergoing testing.Design binding adjustment unit to control the effect of ski boot snap tightness on flexion stiffness test results.To obtain the standard set load (120N) of this test device by analyzing the stability and accuracy of Q-value distribution of ski boot test samples under different set loads (60N~200N), and then to evaluate the test effect of the device by testing three different flexion stiffness values of ski boots under the standard set load. Different binding forces (0~60N) were set to study the effect of the looseness of ski boot snaps on the flexion stiffness test results. Conclusion: Under standard set load conditions, the relative standard deviation (RSD) of the Q-value test results for three different flexion stiffness values of ski boots were less than 1% and the distribution points were basically within the 95.44% prediction band, indicating that the device has high testing accuracy and reliability.The device is capable of adjusting the amount of binding force to quantify the effect of ski boot binding tightness on ski boot flexion stiffness test results.The experimental results show that the tightness of the ski boot buckle can have a negative correlation on the deflection angle of the ski boot under test.