Optimization of H-shaped thin-walled energy absorber by Taguchi method and a new theoretical estimation for its energy absorption

To improve energy absorption performance of thin-walled sections, the present research work investigates energy absorption capability of a type of thin-walled profiles with H-shaped cross-section during quasi-static flattening process and optimizes its geometry, using the Taguchi method; and also derives some theoretical formulas to predict total absorbed energy by the H-shaped section. Two theoretical analyses are performed based on two different material models consist of Power hardening and Rigid-Linear work hardening. In each theoretical analysis, general formulations are derived to estimate absorbed energy by a plastic hinge line and an unbending process. In the optimization trend, design of experiment (DoE) is carried out by the Taguchi method. Due to experimental limitations in providing the various samples with different geometrical dimensions, ABAQUS/Explicit software is used. As control factors, influences of geometrical parameters and lateral loading angle are studies on specific energy absorption (SEA); and design of optimum geometry of the H-shaped profile is discussed. Contribution percentage of each control factor is determined on the SEA of the profile, which provides important reference for designing the H-shaped profile in practical energy absorption applications. Results show that wall thickness of the profile cross-section has the highest effect on the SEA of the H-shaped section with contribution ratio of 47.02%. Furthermore, loading angle has the smallest influence on the specific energy absorption capacity. Finally, optimum geometry of the profile is introduced. Also, comparison of the obtained results by theoretical predictions and numerical simulations illustrates precision and acceptable accuracy of the derived theories.