Cold-formed structure connections utilizing gusset plates are usually semi-rigid. This paper investigates the behaviours of rectangular gusset plates in cold-formed connections of elements whose columns and beams are made with lipped back-to-back C-sections. Methods of calculating strength and stiffness are necessary for such semi-rigid joints. The main task of this paper is to determine a method capable of calculating these characteristics. The proposed analytical method could then be easily adapted to the component method that is described in part 1993-1-8 of the Eurocode. This method allows us to calculate both the strength and stiffness of rectangular gusset plates, assuming that the joint deforms only in plane. This method of design moment resistance calculation was presented taking into account that an entire cross-section shall reach its yield stress. A technique of stiffness calculation was presented investigating the sum of deformations acquired at the bending moment and from shear forces which are transmitted from each beam bolt group. Calculation results according to the suggested method show good agreement of laboratory experimental results of specimens with numerical simulations. Two specimens of beam-to-column connections were tested in the laboratory. Lateral supports were used on the specimens to prevent lateral displacements in order to better investigate the behaviour of the rectangular gusset plate in plane. Experiments were simulated by modelling rectangular gusset plates using standard finite element software ANSYS Workbench 14.0. Three-dimensional solid elements were used for modelling and both geometric and material nonlinear analysis was performed.
The paper presents achievements in gluing technique in steel and aluminium structures. Adhesives currently in use and available on the market are characterized from the point of view of their mechanical properties. Design rules of adhesive connections and basic methods for their calculations are mentioned. The most significant examples of the applications of those joints in steel as well as aluminium structures are shown.
Crossing borders: between literature and science – Italian culture of the twentieth and twenty-first centuries has offered significant examples of renewal through crossing boundaries between different disciplines. Several writers (Levi, Calvino, Gadda, Sinisgalli, Del Giudice, Giordano, Arpaia, Odifreddi) have overcome the dichotomy between the two cultures that was denounced by Charles Snow in 1959. Sixty years after the famous essay by Snow, the paper will show several examples of connections between literature and science, by using the concept of the “four frontier customs”: “the transit”, “the trespass”, “the alliance”, and “the conflict”.
The article discusses the problem with modifications of plans of water areas and the forms of their borders which have been inscribed into the history of all city structures related to water. It can be observed that the modifications made in recent decades very often concern the transformations of former industrial sites. Many such structural changes are taking place within signifi cant areas which have fragmented central parts of cities and created voids in the urban fabric. They are being applied to many former shipyards and ports. Research shows that the formation of new connections between land and water in these transformation processes is essential. More frequently, those conversions that are currently being realized change the constructions of wharves and lead to the development of plans drawing new borders between land and water. In these cases water is introduced into land areas and new land surfaces are being created over existing bodies of water. These operations can be considered extremely valuable in achieving the intended eff ects of transformations of post-industrial areas. They are perceived as an excellent possibility to strengthen the relationship between the city structure and water. At the same time they create an opportunity to achieve a high quality of architectural and landscape solutions and the quality of spaces in both social and economic terms.
Overseas mining investment generally faces considerable risk due to a variety of complex risk factors. Therefore, indexes are often based on conditions of uncertainty and cannot be fully quantified. Guided by set pair analysis (SPA) theory, this study constructs a risk evaluation index system based on an analysis of the risk factors of overseas mining investment and determines the weights of factors using entropy weighting methods. In addition, this study constructs an identity-discrepancycontrary risk assessment model based on the 5-element connection number. Both the certainty and uncertainty of the various risks are treated uniformly in this model and it is possible to mathematically describe and quantitatively express complex system decisions to evaluate projects. Overseas mining investment risk and its changing trends are synthetically evaluated by calculating the adjacent connection number and analyzing the set pair potential. Using an actual overseas mining investment project as an example, the risk of overseas mining investment can be separated into five categories according to the risk field, and then the evaluation model is quantified and specific risk assessment results are obtained. Compared to the field investigation, the practicability and effectiveness of the evaluation method are illustrated. This new model combines static and dynamic factors and qualitative and quantitative information, which improves the reliability and accuracy of risk evaluation. Furthermore, this evaluation method can also be applied to other similar evaluations and has a certain scalability.
This paper proposes the development of a formation control algorithm of multiple acoustic underwater vehicles by employing the behaviour of autonomous mobile agents under a proposed pursuit. A robust pursuit is developed using the distributed consensus coordinated algorithm ensuring the transfer of information among the AUVs. The development of robust pursuit based on characteristics of multi-agent system is for solving the incomplete information capabilities in each agent such as asynchronous computation, decentralized data and no system global control. In unreliable and narrow banded underwater acoustic medium, the formation of AUVs based distributed coordinated consensus tracking can be accomplished under the constant or varying virtual leader’s velocity. Further, the study to achieve tracking based on virtual leader AUV’s velocity is extended to fixed and switching network topologies. Again for mild connectivity, an adjacency matrix is defined in such a way that an adaptive connectivity is ensured between the AUVs. The constant virtual leader vehicle velocity method based on consensus tracking is more robust to reduce inaccuracy because no accurate position and velocity measurements are required. Results were obtained using MATLAB and acquired outcomes are analysed for efficient formation control in presence of the underwater communication constraints.
The aim of the article to assess the functioning of the NewConnect market over 10 years from the organizer’s and participants’ perspective. This helps to diagnose the most important organizational advantages and problems of the Polish MTF, determine further development prospects and propose potential changes to neutralize the negative factors. To illustrate the problem, a comprehensive analysis will be made of aggregated statistical data from 2007–2017, which show the changes and trends on this market, and additionally include the data comparing the current state of the NewConnect market with other alternative markets organized by European stock exchanges.
The conducted research does not allow to view the NewConnect market as an organizational success. The analysis identified a number of problems in the functioning of the Polish MTF, ranging from the inappropriate organization of the primary market, resulting in the admittance of too high a number of issuers of dubious credibility, to the consequences appearing on the secondary shares market. It does not give unambiguous grounds to expect positive prospects for the market development in the future. In order to stop unfavorable trends and to improve the issuers’ quality, a discussion on the regulations regarding issuers’ admission, i.e. the size of the minimum equity, IPO, capitalization and the issue price of the debuting company, should be initiated.
While working on the oeuvre of P.F. Strawson (1919–2006), and especially on his metaphysics, I had a unique opportunity to exchange ideas with this eminent exponent of Oxford philosophy. Those exchanges, of which some have been reflected in private correspondence and in a published reply to one of my papers, were focussed on various interpretative questions. Three threads of those discussions seem especially pertinent for grasping the gist of Strawson’s philosophy and its general orientation. The first one concerned the nature of philosophical analysis, or to be more precise, the connective model of it, favoured by Strawson, and its relationship with the idea of concept presupposition. The second thread had to do with the position taken by the Oxford philosopher in the realism debate on three levels: semantic, epistemological, and metaphysical. Strawson made every effort to take a realist stand in this debate and avoid antirealism in any of its forms; however, his realism is in many respects very moderate and not so distant from antirealism. Similarly moderate was his stand in the traditional debate about universals, constituting the topic of the third thread of the exchanges with Strawson. He claimed that universals exist, but at the same time emphasized that they are objects of pure thought alone and as such do not form a part of the spatiotemporal world in which we live. One cannot also say much about the relation of exemplification in virtue of which universals manifest themselves in the world as particular instances. Presentation and elaboration of these three threads has led to the conclusion that although Strawson was a deeply systematic thinker, he avoided wide-ranging and ambitious statements and radical views. In characteristically minimalist way he dispelled some questions, and the ultimate resolution of many crucial and fundamental issues were for him choice and taking a particular attitude or stance.
Experimental tests of steel unstiffened double side bolted end-plate joints have been presented. The main aim of the conducted tests was to check the behavior of joints in an accidental situation and possibility of creating secondary mechanism, i.e. catenary action in the scenario of column loss. Two types of end plate joints were tested: flush end-plate (FP) and extended end-plate (EP) with different thickness and different number of bolt rows in each. The tests were carried out on an isolated cross beam-column-beam type system until joint failure. During tests the available moment resistance and rotation capacity of bending joints and also values of tension forces in the beam were determined. The joints with extended end-plate have demonstrated higher bending and rotational capacity than flush end-plate. Significant deformation of column flanges, web and end plate were observed. The fracture of bolts was the failure mode of joints. Obtained results of axial force values in beam exceeded standard requirement what confirmed that the joints with unstiffened web column, flush or extended end-plate possess the ability of development the catenary action.