Advanced Materials Research Vols. 945-949

Abstract: The traditional stress severity factor (SSF) approach was applied to analyze the life of aircraft multi-fastener joint. 3-D model was established under simulated state of practical assembling using CATIA, and then the model was imported into ABAQUS to analyze the detail stress state of aircraft multi-fastener joint. The life of aircraft multi-fastener joint was estimated by amending the SSF method. The example shows that the fatigue life by the approach is closer to the experimental result.

Abstract: ANSYS software has provided complete and accurate solutions for composite laminate analysis and provided a set of special elements for different composite structures such as laminated plates, beams, solid structures and stiffeners. Fiber composite materials have been widely used to critical components of aircrafts, automobiles, mechanical, and marine structures. Since uncertainties associated with geometric tolerances, material properties, and boundary conditions widely exist in practical engineering problems. The probability approach is the most popular way to quantify uncertain parameters and perform the reliability analysis. The paper researches on the reliability analysis of the composite panels using ANSYS software. The numerical example is given, it is shown that the response surface method (RSM) can reduce the computational efforts comparing with Monte Carlo simulation (MCS).

Abstract: Reliability of laminate structure is deeply influenced by uncertainties such as fiber properties, loads and design sizes. It is very difficult to evaluate the reliability and sensitivity of laminate structure because that laminate structure is anisotropic and the limit state function (LSF) is a high nonlinear function. In this paper, reliability and sensitivity are evaluated by using first order reliability method (FORM), response surface method (RSM) and Monte Carlo simulation (MCS). The study aims to find a numerical method to evaluate the reliability and sensitivity of laminate structures efficiently and accurately. An example of laminate with a large number of variables is analyzed. The results obtained by using different methods are compared in terms of efficiency and accuracy. It is shown that FORM is not accuracy, and RSM has a very good accuracy and efficient in terms of reliability, but the accuracy of sensitivity obtained by using RSM is not good enough.

Abstract: Traditional trellis support was mainly used in deep mining roadway of Kailuan group. With the increase of mining depth, section of roadway and deformation of surrounding rock also increased gradually. As a passive support ways of roadway, trellis support had been unable to meet the requirements of high yield and high efficiency comprehensive mechanized mining. Therefore, anchor bolt supportis in urgent need to turn passive support into active support and to ensure the safety and the stability of surrounding rock of roadway, meanwhile, the cost saving and boosting yield was made sure. This paper is based on the physical and mechanical parameters of coal seam roof and floor of working face 1357w, numerical simulation method was took, and the parameters of anchor bolt support suitable for the roadway with working face were also studied. The result of study could provide theoretical basis for later projects.

Abstract: In this paper, design of roadway with stope working face Yeqing 8459 had been optimized combined with geological characteristics of the working face based on the actual measurement of ground stress and mechanical properties of coal rock of Yangquhe mine in Feng Feng mining area. Analyzing eight kinds of roadway support design scheme through numerical simulation and evaluating the supporting effect of each supporting design scheme, designating the construction guidelines ultimately.

Abstract: This paper takes typical stoping of deep-mine dynamic pressure working face of Zhaogezhuang mine of Kailuan mining area for the research background, relieving the dynamic pressure of roadway of burst tendency through building defect method in dynamic pressure roadway. Putting forward the theoretical solution of defect method in dynamic pressure roadway based on elastic-plastic theory;Taking numerical simulation method in view of the material inhomogeneity of actual engineering geological, researching the characteristics of stress distribution of roadway surrounding rock after relieving in defect method; Applying the theory to the stoping of deep-mined impact working face, and the implement effect is good on the spot.

Abstract: A finite element model ships, for example design test condition of the underwater explosion, selection of explosive package quantity is 1000KG TNT, the explosive location along the direction of the ship with the bow, midship and stern, the angle of attack in three exploded cross section have 90 degrees, 60 degrees, 45 degrees, 30 degrees and 0 degrees. According to the current standard to calculate the ship damage radius, critical radius and safety radius of specific values under the effect of underwater explosion, interpolation calculation and draw the envelope. Analysis shows that the vitality of ships and shock-resistance is not only related to the explosive distance, also related to the attack position.

Abstract: The instability failure of coal and rock mass occur frequently in deep mining. However, this destruction occurs with abnormal intensity and suddenness, with hardly any obvious macro precursors. The ability to extract this precursory information and make certain the relationship among the parameters is therefore important. During the process of instability and failure of coal samples, the evolution characteristics of deformation field were monitored by digital image correlation system. Base on the researches, the appearance of the deformation localization band could be divided into three time periods for the samples which all had splitting failure. During period I, the relative sliding component increased rapidly. During period II, the relative tension component increased rapidly. During period III, both the relative tension and relative sliding components increased rapidly.

Abstract: Based on the distribution of in-situ stress and the special conditions of the large mining height in one mining area, the author conducted the analogy stimulation test of the mine pressure behavior and the roadway deformation law. This research, mainly based on the geographical conditions of 1 to 2 coal seam of this mining area, stimulated the mine pressure behavior of the working face and the roadways, as the mining height is 5meters and 6meters. Through this analogy stimulation test, the mine pressure behavior of working face, in the mining process with large mining height, is analyzed and summarized.

Abstract: Stress-strength interference model has been widely used for reliability analysis of structures.Strength degradation of a structure is a common phenomenon in engineering. To evaluate the structure reliability in the case of strength degradation over time, the strength degradation is represented by a gamma process and the stress applied on a structure is represented by the Poisson process in this paper. Then a time-dependent stress-strength interference model is suggested by employing numerical integration method. With this model, the structure reliability can be evaluated more accurately.