In this paper, a smoothed weighted function with the compact support is suggested to improve the numerical accuracy of blending elements for the extended finite element method (XFEM) applied to the crack problem. Such a weight function consists of the shape functions used for the meshless method, reflecting the characteristics of the enriched bases inside the blending element. The effectiveness of this weight function is validated through the numerical examples.

The use of elastic elements in actuators can be effective in improving their performance. The present paper examines the different layouts of the elastic element in actuators, choosing the appropriate design, and then designing a series elastic actuator for use in an active knee orthosis. For this purpose, the design elements of actuators were extracted using the knee data for walking. In the next step, considering the effect of the spring stiffness on the energy consumption and actuator’s peak power, its optimum amount for gait was calculated. Afterwards, the effect of adding the spring has been shown at an optimal value. Since the human knee in a gait cycle involves position and force control, designing an efficient controller to track the force and position of the knee during the gait cycle is the next section of this study. Due to the specific application of this actuator, its volume and size are important for the user. For this reason, it is necessary to design and construct an actuator with a suitable size and weight, with good output. For this purpose, a lightweight and low volume actuator was fabricated.

Failure analyses require more and more reliable and robust approaches to structural response prediction. This represents a quite complex task to be accomplished especially when dealing with historical or ancient constructions in seismic geographic areas. The paper is aimed at providing approaches to the analysis of buildings alternative to simplified methods usually adopted in professional practice, which do typically involve drastic simplifications of the fabric. The approach allows developing full holonomic non-linear analyses for forecasting the behavior of structural panels present in the structural system, and it results in higher reliability and flexibility than ordinary procedures that are generally adopted in commercial software and are typically based on gross simplifications of the real structure. The presented method allows taking into account the real geometry of the masonry building under analysis, also including a number of elements such as architraves, tendons or reinforcements possibly incorporated into the walls. Besides the consistent improved reliability in performing structural analyses under quasi-static loads, the main potential of the approach is related to the possibility of developing its extension for performing dynamic analyses quite easily.

This paper presents a numerical investigation on the flexural performance of a novel cementitious reinforced GEM-TECH material using finite element method. A discrete nonlinear FE model using the commercial software ANSYS was employed to model a steel-reinforced GEM-TECH beam. Element SOLID65 was used to model the cementitious material while LINK180 element was used to model the reinforcing bars and stirrups. For model validation, FEA results and crack plots were compared to those obtained from the experimental results of five reinforced GEM-TECH beams: three beams designed with target density of 1810 kg/m3 and two beams with target density of 1600 kg/m3. Both load-deflection plots and the failure mode crack plots predicted by the FE model were in good agreement with the experimental results.

In the present paper, the theory of generalized photo-thermoelasticity under fractional order derivative was used to study the coupled of thermal, plasma, and elastic waves on unbounded semiconductor medium with a cylindrical hole during the photo-thermoelastic process. The bounding surface of the cavity was traction free and loaded thermally by exponentially decaying pulse boundary heat flux. The medium was considered to be a semiconductor medium homogeneous, and isotropic. In addition, the elastic and thermal properties were considered without neglecting the coupling between the waves due to thermal, plasma and elastic conditions. Laplace transform techniques were used to obtain the exact solution of the problem in the transformed domain by the eigenvalue approach and the inversion of Laplace transforms were carried out numerically. The results were displayed graphically to estimate the effect of the thermal relaxation time and the fractional order parameters on the plasma, thermal and elastic waves.

In this paper, the edgewise and flatwise compressive behaviour of an innovative sandwich panel, mainly developed for quick assembly of post-disaster housing as well as load bearing panels for pre-fabricated modular construction and semi-permanent buildings, is investigated experimentally and by finite element modelling. The panel is composed of two 3-D high-density polyethylene (HDPE) sheets as the skins, filled with high-density Polyurethane (PU) foam as the core. HDPE sheets manufactured with a studded surface considerably enhance the stress distribution and buckling performance of the sandwich panel. Material characterisation tests and flatwise compression and edgewise compression experiments were performed in accordance with ASTM standards to evaluate the compressive strength and the load-carrying behaviour of the sandwich panels. A finite element analysis and validation were also conducted to model the compressive behaviour of sandwich structures. Results demonstrate that the developed sandwich panel exhibits very good compressive performance.

This paper illustrates an innovative manufacturing procedure for producing handcrafted interlocking stabilized compressed earth blocks (ISCEBs). A comparison of the mechanical properties of ISCEBs is conducted to assess the influence of varying components. The ISCEBs are manufactured by employing different block densities with three distinct mixtures (earth, earth and lime, earth and straw) and by using a human-powered machine named Float RAM 1.0 Press. The manual press was conceived for regions with limited access to technology and allows the production of interlocking blocks via two modes of compaction: mono-directional and bi-directional. A production average of approximately 30 blocks/hour corresponding to the work of three people is achieved. Three-point bending tests and uniaxial compression tests are carried out to investigate the ISCEB mechanical behaviour. The improvements obtained by incorporating additives into the subset of ISCEBs made from a pure earth mixture are tested. The aim of this work is to identify, for this specific technology, the relationship between production parameters and the consequent behaviour of different stabilization methods. A correlation is found between the compaction force and the compression strength of ISCEBs. The addition of lime increases strength and causes the blocks to exhibit a brittle behaviour. Moreover, the incorporation of straw fibres improves the tensile strength and ductility without significantly affecting the compression strength of the blocks. Energy-based parameters are obtained for all the tests, allowing the assessment of the ISCEB mechanical and dissipation properties.

Simulation and visualization of the mechanical components have become a predominant phase during the design and the production stages. Several means are used to improve the design and to reduce study time. Today, the powerful hardware and the software available on the market have contributed greatly on the improvement of design, visualization and manufacturing process of complex parts (turbine blade). In this context, our study is a contribution to the establishment of a methodology to a CAD modelling and finite element analysis, which allows us to identify the mechanical behavior of a gas turbine blade. The profile of the blade turbine model is obtained after regeneration using the CATIA V5R20 software from the retro-design technique using a FARO-type scanner. The turbine blade is analyzed under a static mechanical behavior. It has been observed that the maximum stresses and deformations are located in the vicinity of the root and the upper surface along the turbine blade. On the other hand, the elastic energy is located at a distance from the root of the turbine blade.

In this paper, an innovative and efficient sandwich panel is proposed for the structural walls for quickly assembled post-disaster housing, as well as load bearing panels for pre-fabricated modular construction and semi-permanent buildings. This study focuses on the flexural and shear behavior of the innovative sandwich panels, which is composed of two 3-D high density polyethylene (HDPE) skins, and high-density Polyurethane (PU) foam core. An experimental study was carried out to validate the effectiveness of this panel for increasing the ultimate bending strength. A series of experimental tests were performed on medium-scale specimens to characterize their core shear behavior. Then, some supplementary tests were run to determine the panels’ flexural and shear stiffness. The numerical and experimental investigations show that the 3-D-HDPE sheets, manufactured with a studded surface; considerably enhance the pull-out and delamination strength. Good agreement has been observed between the numerical and experimental tests.

The battery packs are one of the most vulnerable parts of satellites for damages induced by vibration and shock during launch process. This is due to their considerable weight which increases their susceptibility for structural damage and short connection. Therefore, the related components have to pass successfully ground dynamic and vibration tests in order to verify the dynamic design of such component and ensure the successful performance of a space mission. In this paper, first a new design is presented for a battery pack of a microsatellite and then the verification of designed and manufacturing pack is done by performing some vibration tests based on the European space standard (ECSS). It was shown that the designed battery pack which uses circular or radial type arrangement for the battery cell layout can suitably pass the mechanical vibration tests applied to the pack during the lunch.