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This article details the experimental and numerical results on the energy absorption performance of square tubular profile with circular discontinuities drilled at lengthwise in the structure. A straight profile pattern was utilized to compare the absorption of energy between the ones with discontinuities under quasi-static loads. The collapse mode and energy absorption conditions were modified by circular holes. The holes were drilled symmetrically in two walls and located in three different positions along of profile length. The results showed a better performance on energy absorption for the circular discontinuities located in middle height. With respect to a profile without holes, a maximum increase of 7% in energy absorption capacity was obtained experimentally. Also, the numerical simulation confirmed that the implementation of circular discontinuities can reduce the peak load (P max ) by 10%. A present analysis has been conducted to compare numerical results obtained by means of the finite element method with the experimental data captured by using the testing machine. Finally the discrete model of the tube with and without geometrical discontinuities presents very good agreements with the experimental results.

Many hand accidents are reported around the world resulting in a necessity to perform a procedure of amputation of the hand. For this consideration, a large number of hand prostheses have been designed. However, the mechanical design of these prostheses present challenges such as kinematic functionality, strength, and cost. The present article analyses the mechanical design of a low-cost practical hand prosthesis using the finite element method with the help of Abaqus commercial software. Functional and technical requirements were considered to consider the biomechanics of the human hand. The hand prosthesis was conferred with 14-degrees-of-freedom (DOF), which gives it the capacity for grips associated with security, stability, dexterity, and sensibility. Additionally, due to practicality and low-cost manufacturing techniques, fused deposition modelling with acrylonitrile butadiene styrene (ABS) is proposed. The evaluation of the hand prosthesis was carried out by tensile, flexural, and torsional load conditions. Finally, the mechanical effectiveness of the designed prosthesis was demonstrated since maximum stresses close to 13 MPa were computed, which are less than the yield stress of ABS.

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Recently, multi-cell structures have received increased attention for crashworthiness applications due to their superior energy absorption capability. However, such structures were featured with high peak collapsing force (PCL) forming a serious safety concern and this limited their application for vehicle structures. Accordingly, this paper proposes windowed shaped cuttings as a mechanism to reduce the high PCL of the multi-cell hexagonal tubes, and systemically investigates the axial crushing of different windowed multi-cell tubes, and also seeks for their optimal crashworthiness design.Three different multi-cell configurations were constructed using wall-to-wall (WTW) and corner-to-corner (CTC) connection webs. Validated finite element models were generated using explicit finite element code, LS-DYNA, and was used to run crush simulations on the studied structures. The crashworthiness responses of the multi-cell standard tubes (STs), i.e. without windows, and multi-cell windowed tubes (WTs) were determined and compared. The WTW connection type was found to be more effective for STs and less favorable for WTs. Design of experiments (DoE), response surface methodology (RSM), and multiple objective particle swarm optimization (MOPSO) tools were employed to find the optimal designs of the different STs and WTs. Furthermore, parametric analysis was conducted to uncover the effects of key geometrical

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