Advanced Materials Research Vols. 945-949

Abstract: Three groups of specimens were designed in this paper to compare the performance of rigid joints transferring forces outside box columns to that of traditional joints by finite element method program ANSYS. The influences of deviation of verticality in columns on stiffness, yielding capacity, and ultimate carrying capacity were analyzed. The evaluation of working performance by adding force-transforming plates could be found. The thickness and width of adding plates would be the key parameters of steel frame joints. This paper put forward the optimal range of design parameters.

Abstract: Body section is the main part of the roadheader and its stability had serious impact on the working efficiency and the stability of roadheader. It is under all the dynamic impact from the other parts of roadheader. Since complex force condition, violent and irregular vibration, the stability of body section is particularly important and the mechanical parts design plays very important roll to the EBZ160 Roadheader. The paper gets the vibration modes, maximum amplitudes of the body section and where they appear by modal analysis of two main parts of the body section whose maximum order is five. According to the result, more attention must be paid to the complex force condition, violent and irregular vibration of the body section in the design.

Abstract: This summary report is based on the experimental and numerical research of thin-walled cross-section’s compression resistance and shear strength of their joints carried out in St. Petersburg State Polytechnical University and HAMK University of Applied Sciences, Sheet Metal Centre. Current situation on Russian market concerning the usage of cold-formed thin-walled cross-sections is aimed to find out a base foundation to start up a stipulation of the elements under discussion in the building industry (Kolesov et al. 2007; Peleshko, Urchenko 2009; Zhmarin 2012). Some questions about the compression resistance of such cross-sections were raised on different conferences (Vatin, Sinelnikov 2013; Winter 1952; Yu Wei-Wen et al. 1996) by scientific community and by companies such as Rautaruukki Oyj (Finland). Steel galvanized C-and U-profiles and thermo-profiles are types of thin-walled cross-sections that are normally used in small houses construction (Shatov 2011; Smaznov 2011). Thermo-profiles have slots in web that decrease the thermal flow through the web, but have a negative effect on strength of the profiles (Schafer, Pekoz 1998; Vatin, Popova 2006). These profiles were an object of the research. Investigations carried out included tests to prove the compression resistance of the thin-walled cross-sections and shear strength of stud-to-rack joints. Numerical modelling of thin-walled cross-sections (Cheng, Schafer 2007) was done with contemporary analysis software (SCAD Office, Lira) (Kriksunov et al. 2010; Perel'muter et al. 2009) using the finite element method (FEM) (Bayan et al. 2011; Gordeeva, Vatin 2011; Rasmussen 2009).

Abstract: For the prestressed plane entitiy steel structure topology optimization design which design variables include the cable pretension value, unit size and the structural topology, the optimized mathematical model which objective function is the minimum structural weight is established with consideration of the constrains of stress and displacement. As for the solving method, firstly we need to determine the pretension applying to the cable according to full stress design and choose the unit size; then we need to conduct displacement sensitivity analysis to delete the low sensitivity unit to realize the structural topology optimization design. The example result is in conformity with the corresponding system of mechanical performance, and it indicates that the method proposed in this paper is effective.

Abstract: In the tradition Evolutionary Structural Optimization (ESO), the maximum value of inefficient material efficiency equates to the product of the rejection rate and the maximum value of all material efficiency. However, the rejection rate cannot be adjusted flexibly according to the trend of optimization, and the maximum value of all material efficiency may mutate abruptly (become larger or smaller). These two factors may cause that material may sometimes be removed less, sometimes too much. In view of the defect of the traditional evolutionary structural optimization, the Evolutionary Structural Optimization Using the Minor Value of Material Efficiency (ESO-MVME) is proposed in this paper. The maximum value of the inefficient material is close to the minimum value of material efficiency, and has nothing to do with the reject rate and the maximum value of material efficiency. The study finds that the ESO-MVME method has a better applicability than the traditional ESO, and can obtain a better optimization result.

Abstract: In order to solve the potential safety problem due to the explosion of coal mine caused the severe deformation of the front door not being opened normally and the emergency escape hatch was designed unreasonably, three types of structure model with emergency escape hatch being set in transition compartment as entrance and different locations of life supporting compartment as exit, which can avoid the potential safety problem above mentioned. Numerical simulation of antiknock impact performance of the three refuge cabins were calculated and analyzed by using the finite element software of LS-DYNA.The results indicated that the antiknock performance of structures could reach specifications, which could provide a new idea for the development of mine refuge chamber cabin.

Abstract: Coal mine roadway roof and sides often take strong support, and the floor support is weak or none support. Because of the high stress, roadway damage phenomena have occurred often, take reasonable repair plan is the key to the recovery project. Reasonable repair plan not only can effectively control the deformation of surrounding rocks, but also can reduce the maintenance cost. According to the surrounding rocks’ property and depth of roadway in Anhui Huainan Pan-III mine, using FLAC3D numerical simulation software, analysis of the effect on plastic zone, surrounding rocks stress and displacement under different floor support, and put forward the repair plan to this coal, the related research conclusions can provide reference for design and construction to similar engineering.

Abstract: this paper considers the possibility of applying the ideas of dimensional analysis in optimization problems of building structures. The mathematical formalism for this opportunity are encouraged to use the method of geometric programming. Demonstration considered optimization problem reinforced concrete slab, which is solved with the help of the program developed by the author. The possibility of obtaining as a result of optimization of analytical expressions for the economic criteria of similarity best options. Also shows the possibility of obtaining optimal solutions in analytical form for those variables in the original problem are not uniquely defined. The very ambiguity of the definition of the variables of the original problem may not be obvious, and it appears in the process of optimizing, which is one of its results.

Abstract: This paper presents intensity calculation of the cylinder block of the underwater instrument cabin which has outer diameter of 220mm, thickness of 7.5mm, and length of 1660mm. With simplifying force of the cylinder block to the problem of elastic plane stress, its’ internal stress is calculated under internal pressure and external pressure, in the case of the simulation tests and working state. Calculations and simulation indicate that: its’ maximum internal stress exceeds the elastic yield limit at 30MPa, and the cylinder block cannot work in 3000 meters underwater. At the same time, it proves that the maximum internal stress first starts from the inwall of the cylinder block with the method of using internal pressurization test, which is consistent with the working state, but because the maximum internal stress in the test state is less than the maximum internal stress in the working state, the test method may misjudge. Finally, through calculation, it is specified that the theoretical work water depth of the cylinder block is 1300 m and the axial deformation is about 0.5 mm, radial deformation is about 0.1mm, which provides reference for the seal design.

Abstract: The multi-modal parameters which are composed of the curvature mode and the flexibility curvature are used to identify the damage on the base of finite element method model based on continuous beam. It has been proved that multi-mode parameters are considered as the networks inputting parameters, and the location of the structure damage can be accurately determined and the damage degree can be obtained by the neural networks. It has indicated that this neural network has a excellent identification ability with good fault tolerance and robustness.