Laminated glass is a composite structure consisting of a polymeric interlayer (e.g., polyvinyl butyral PVB) sandwiched between two glass plies. Due to the increasing use of laminated glass (LG) in advanced industries such as automotive sectors, it is of much importance to investigate the fracture behavior of such structures. One of the most critical steps in outlining the fracture behavior of laminated glass is the accurate determination of the fracture energy of the interlayer, usually, polyvinyl butyral (PVB), which is obtained from experimental methods. So far, various laboratory samples have been presented to measure the fracture energy of laminated glass, each of which has its advantages and limitations. In this paper, a new loading setup is proposed for the determination of mixed-mode I/II fracture energy in a rectangular-shape laboratory sample of laminated glass. The loading setup consists of a rectangular beam under a four-point bending which has been analyzed by the commercial ABAQUS software package. By utilizing this specimen, the fracture energy of the combined modes from pure mode I to pure mode II in the PVB interlayer can be measured. The proposed geometry here is simpler than other available geometries in the literature and also it does not require a complex loading mechanism. The effects of crack length ratio and also the support distance on fracture parameters such as and are well investigated.

This paper describes an experimental program developed to investigate non-bearing spliced composite short column connections made of Glass Fiber Reinforced Polymer (GFRP) that are subjected to axial loading. This study provides aspects such as the load-bearing capacity of the connection, failure modes, load distribution in the connection, displacement in the joint, stiffness, and compressive strength. The design of the joint in this study that connects two 350mm GFRP H-sections to form a short column connection is based on euro codes BS EN 1990 and BS EN 1991, which are used to design steel splicing connections for beams and columns. Four design specifications models are made depending on the positioning of the cover plates in the inner flange, outer flange, and web region of the H-sections to examine the requirement of a specific cover plate, and the H-sections are bolted to each other using M8 8.8 grade steel bolts. The samples tested in this study indicated a dominant failure in the flange region, with model-4 providing 92.83% compressive strength when compared to an uncut GFRP short column.

The set covering problem is to find the minimum cardinality set of locations to site the facilities which cover all of the demand points in the network. In this classical problem, it is assumed that the potential facility locations and the demand points are limited to the set of vertices. Although this problem has some applications, there are some covering problems in which the facilities can be located along the edges and the demand exists on the edges, too. For instance, in the public service environment the demand (population) is distributed along the streets. In addition, in many applications (like bus stops), the facilities are not limited to be located at the vertices (intersections), rather they are allowed to be located along the edges (streets). For the first time, this paper develops a novel integer programming formulation for the set covering problem wherein the demand and facility locations lie continuously along the edges. In order to find good solutions in a reasonable time, a matheuristic algorithm is developed which iteratively adds dummy vertices along the edges and solves a simpler problem which does not allow non-nodal facility locations. Finally, a Benders decomposition reformulation of the problem is developed and the lower bounds generated by the Benders algorithm are used to evaluate the quality of the heuristic solutions. Numerical results show that the Benders lower bounds are tight and the matheuristic algorithm generates good quality solutions in short time.

Recently, due to their extraordinary strength-to-weight ratio and multi-functional applications, three-dimensional woven fiberglass sandwich structures have become a well-received topic by researchers and manufacturers. Nevertheless, using light and foam absorber materials as injected fillers within sandwich cores can improve their overall mechanical performance and, in particular, their fracture toughness behavior. This study evaluates the fracture toughness of three-dimensional woven fiberglass sandwich panels filled with natural nano-structured zeolite/polyurethane foams injected between their parallel panels. The Single-Edge Notched Bend test was carried out to understand the effect of the injected foam on the mode-I fracture toughness response. It is demonstrated that the polyurethane foam reinforced with natural nano-structured zeolite particles highly improved the fracture toughness of sandwich core panels. It was found that the presence of vertical glass yarns within the sandwich panel gallery resulted in a significantly higher toughness compared with typical sandwich panels of no reinforcing vertical columns confirmed by the crack propagation and observed failure mode. The SEM and EDX analyses were used to better understand the correlations amongst the specimen morphology, the cracks behavior, and the toughness exhibited by the fabricated specimens.

In this study, the influence of the volume fraction of the martensite phase as well as the size of the martensite particles on the mechanism of particle fracture in dual-phase steel were examined. A combined continuum/dislocation based approach was used in order to model the average stress in the martensite particles. It was found that the model predictions are in accordance with the experimental results. For the same volume fraction of the martensite particles, the model predicts an increase of the internal stress and the average stress in the martensite particles with increasing the particles size. Since the fracture strength of the martensite depends on its volume fraction, the particle size has no effect on the mechanism of particle fracture. Increasing the volume fraction of the martensite particles results in the enhancement of the internal stress in the martensite particles. However, it has a slight influence on the average stress in the particles. Nevertheless, because of decreasing the fracture strength of martensite with increasing its volume fraction, this parameter has a main role in the occurrence of the particle fracture mechanism.

Asphaltic concrete mixtures are among the most common construction materials for the pavement of roads. As a multi-phase composite mixture with randomly distributed aggregates inside the mastic part, the mechanical properties of such materials can be influenced by different factors. Cracking and induced fracture is among the common degradation and failure modes in these construction mixtures that often takes place in cold regions. In this research, the effects of some influencing parameters including temperature, air void percentage and loading rate are investigated experimentally on the fracture toughness (K_Ic) and work of fracture (W_Ic) of hot mix asphalt material. Edge notched semi-circular bend (SCB) specimen was employed to conduct mode I fracture experiments. The thickness of SCB samples were considered as variable and the HMA mixtures were tested with two SCB thicknesses of 30 and 60 mm. The experimental results showed that both fracture toughness and fracture work are increased by increasing the thickness. However, the effect of thickness on the fracture work was much more significant than the K_Ic value. Also, the fracture and cracking resistance parameters were increased by decreasing the temperature and air void content. Both K_Ic and W_Ic values were also increased by increasing the loading rate in the investigated range of 1 to 8 mm/min. The most influencing parameters on the change of fracture resistance parameters were the temperature, loading rate, air void content and thickness, respectively.

Multicriteria Decision Making (MCDM) is one the most important branches of decision theory. Due to the fact that MCDM methods have the utmost significance in management, scholars try to develop more MCDM methods. Since calculating the weights of criteria is an important step in any MCDM method, increasing the accuracy of weight calculating methods can highly affect these methods. This accuracy can be improved by less pairwise comparison between criteria. To this end, the present study seeks to make a comparison between two new weight calculating techniques, namely BWM and FUCOM in a fuzzy environment using a real-world case study Results of this study shows that FUCOM-F provides more reliable results compared to FBWM since its consistency is less than FBWM by a great amount.

Cross-docking is a logistics strategy that consolidates the products of different inbound trucks according to their destinations in order to reduce the inventory, order picking, and transportation costs. It requires a high level of collaboration between inbound trucks, internal operations, and outbound trucks. This article addresses the truck-to-door sequencing problem. Truck-to-door sequencing has been studied by some researchers in different titles such as scheduling and sequencing of inbound and outbound trucks of the cross-dock center. However, previous studies have not considered repeat truck holding pattern. Therefore, it is important to determine the doors and the sequence of the inbound and outbound trucks that should be assigned in a cross-dock center. This paper focuses on optimizing truck-to-door sequencing with consideration of repeat truck holding pattern in inbound trucks in order to minimize makespan. Two methods are considered to solve this problem, including mathematical modeling and a heuristic algorithm. In the first method, a mixed integer-programming model is developed to minimize the makespan. Then, GAMS software is used to solve small-scale problems. In the second approach, a heuristic algorithm is developed to find near-optimal solutions within the shortest time possible and the algorithm is used to solve large-scale problems. The results of the mathematical model and the heuristic algorithm are slightly different and show the good quality of the presented heuristic algorithm.

This project was started when an unknown peak was being detected in the organic volatile impurity (OVI) analysis (using the head-space vapor sampling procedure) of bortezomib (BZB) active pharmaceutical ingredient (API), in pharmaceutical companies. During the OVI analysis of the API of BZB, a huge-area peak with an unknown source appeared in the chromatograms of the gas chromatography with flame ionization detector (GC-FID). The data prepared by GC-MAS revealed that the considered huge peak was 3-methylbutanal (3MBut). But, investigating the synthesis procedures showed that during all the synthesis steps, 3MBut or any other solvent containing this impurity was not being applied. Thus, we had concluded that there is a possibility for emergence of this aldehyde from bortezomib itself. To find out which part of bortezomib might turn into 3MBut, we began to investigate all its molecular structure, and hypothesized that the α-amino-boronic acid part of the molecule turned into 3MBut. The experimental analysis and theoretical quantum chemical calculations confirmed that the α-amino-boronic acid center of bortezomib molecule undergoes a rare and unexpected aerobic oxidation by O2 molecule, even in catalyst and solvent-free conditions. The result of this project not only might make clear the passive source of the 3MBut peak of the OVI of bortezomib, but also, it would suggest to store this API in an inert oxygen-free atmosphere to improve the long-term and accelerated (thermal) stability of this very expensive anti-cancer drug.

One of the most significant parameters which should be considered by all engineers is improving structures’ strength subjected to lateral load. Steel shear wall whose duty is to affect lateral load (wind and earthquake) is a wall which consists of shear part. Application of low yield point (LYP) steel in shear walls allows the employment of moderate and/or stocky infill plates with low yielding and high buckling capacities, which can result in enhanced buckling stability, serviceability, and energy dissipation capacity of such systems. Infill LYP plate is used to improve shear wall behavior which leads to enhancement of stiffness. In the present research, infill plate with spherical appendages is applied, and its impact on plate stiffness, cyclic behavior and energy absorption are investigated. The spherical diameter has been chosen respectively 10 and 20 cm distributed with two patterns (diagonal and plus form). The best performance is for a LYP plate with a 10 cm spherical diagonal pattern.