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Fixation with suture anchors and metallic hardware for osteosynthesis is common in orthopedic surgeries. Most metallic commercial bone anchors achieve their fixation to bone through shear of the bone located between the threads. They have several deficiencies, including stress‐shielding due to mechanical properties mismatch, generation of acidic by‐products, poor osteointegration, low mechanical strength and catastrophic failure often associated with large bone defects that may be difficult to repair. To overcome these deficiencies, a swelling porous copolymeric material, to be used as bone anchors with osteointegration potential, was introduced. The purpose of this study was to investigate the fixation strength of these porous, swelling copolymeric bone anchors in artificial bone of various densities. The pull‐out and subsidence studies indicate an effective fixation mechanism based on friction including re‐fixation capabilities, and minimization of damage following complete failure. The study suggests that this swelling porous structure may provide an effective alternative to conventional bone anchors, particularly in low‐density bone. [ABSTRACT FROM AUTHOR]

A novel design and method of manufacture of laterally corrugated composite tube is proposed. One of the main issues with studying such corrugated composite tubes has been taking out the mandril from the composite specimens, leading to very little, if any, experimental research into this subject. Therefore, as the main novelty of this paper, a multi-step process has been thoroughly explained to overcome these manufacturing challenges, i.e., the use of ABS corrugated mandrels, silicone molds, wax mandrels, filament winding, and finally heating the wax mandrel to melt. At the end of this process, the lateral corrugated composite tube is obtained. There are two different types of specimens: conical corrugated composite tube and cylindrical corrugated composite tube. From each category, two specimens are tested, whose crashworthiness results are then compared with one another to see which design offers better energy absorption capacity. Subsequently, using the experimental data, a finite element model is developed and validated to numerically look into the effect of number of corrugations on the crashworthiness of the structures. To do so, the specific energy absorption (SEA), peak force, mean force, and crushing force efficiency (CFE) of each model have been compared with one another. It is understood from both experiments and numerical study that the conical composite tubes offer better crashworthiness as they can absorb more energy and maintain a higher mean force than the cylindrical ones. For instance, in the experiments, it was observed the conical corrugated composite tube had an SEA of 12.37 kJ/kg, while this value for cylindrical one was 8.38 kJ/kg. Moreover, with an increase in the number of corrugations within a set length for the tube, the energy absorption capacity of the structure can be increased. To provide a better understanding of the observation, with an increase in the number of corrugations from 12 to 18, SEA increased from 9.21 to 12.43 kJ/kg in the cylindrical models, and from 10.80 to 13.01 kJ/kg in conical ones. [ABSTRACT FROM AUTHOR]

In this paper, a meticulous parametric study has been conducted into the crashworthiness of tubes with lateral corrugations. Such corrugated aluminum tubes had already shown to have favourable results as energy absorbers. Consequently, in order to find the optimum structures, the impact of different parameters was to be found. In doing so, first a corrugated aluminum tube and a composite-corrugated aluminum tube were constructed, so that their results could be used to validate the numerical models. Then, 12 tubes were modelled. The variable parameters were the types of corrugations, number of corrugations, and the material of the tubes. These tubes underwent axial and oblique crushing (at 3 different angles). A number of tubes achieved great results in terms of energy absorption, which made them stand out from others. However, in order to find the optimum configuration in each condition, as there was not an obvious pattern based on which crashworthiness parameters would change, complex proportional assessment has been employed (COPRAS), by which, under three circumstances, i.e. results from axial crushing, oblique crushing, and considering both results, the best tubes were chosen. [ABSTRACT FROM AUTHOR]

In this paper, a parametric study has been conducted on aluminum tubes with axially half corrugations. These corrugated tubes have been known for their uniform force-displacement curves as well as their capacity to absorb more energy. To do so, first, the numerical results of 4 tubes have been validated using the results from the quasi-static experiment. Then, the effects of changing the geometrical characteristics have been looked into. The variable geometrical characteristics are number of corrugations and their lengths. Three different levels for the number of corrugations as well as three for lengths have been considered. Among the nine models achieved, some models were found with much more efficient energy absorption. Subsequently, the impact of utilizing corrugations at both ends of the tubes has been investigated as well. By this exploitation, a considerable surge has been seen in the amount of absorbed energy among tubes. In the end, in order to have one best model, complex proportional assessment has been employed (COPRAS), by which, under three circumstances, i.e. results from axial crushing, oblique crushing, and considering both results, the best tube was chosen. [ABSTRACT FROM AUTHOR]