The seamless double layer fabrics are of special uses in industry. The strength of these fabrics is an important parameter due to different forces pushed on them. In the areas where there is a seam, the fabric has the lowest strength in comparison to other parts and this is the key point that shows the reasons of the importance of strength of the seam in the industrial double layer fabrics. Present research provides a new method that increases the strength of the seam in double layer fabrics by shuttle less weaving machines. In this method, two layers of fabrics are joined each other during weaving, a hole is created in the joint of the two layers and the hole is filled by fillers with circular cross section. In fact, fillers with different diameters are employed for this purpose. The fillers with smaller diameters than the hole are used as half fillers and those with larger diameter are used as the full or complete fillers. The strength of these samples are then compared with those with holes and without fillers, two layer samples without hole (joined through the two layers), the sewed two layer samples and single layer fabrics. The results of finite element modeling indicate that the tensile strength of the seam increases by adding fillers to the holes and increasing their diameters. Moreover, it is showed that, increasing of diameter of the hole does not affect the tensile strength of the seam for the samples filled with complete fillers.

This paper aims at presenting a new efficient element for free vibration and instability ANALYSIS of Axially Functionally Graded Materials (FGMs) non-prismatic beams using Finite Element Method (FEM). Using concept of Basic Displacement Functions (BDFs), two- node element extends to three-node element for obtaining much more exact results using FEM. First, BDFs are introduced and computed using energy method such as unit-dummy load method. Afterward, new efficient shape functions are developed in terms of BDFs during the procedure based on the mechanical behavior of the element in which presented shape functions benefit generality and accuracy from stiffness and force method, respectively. Finally, deriving structural matrices of the beam with respect to new shape functions, free vibration and instability ANALYSIS of the FGM beam are studied using finite element method for all types of AFGM beams and the convergence of FEM has been studied. The results from both free vibration and instability ANALYSIS are in perfect agreement with those of previously published.

In order to obtain accurate results from displacement-based Finite Element Method (FEM), it is crucial to introduce accurate shape functions that interpolate the displacement field within an element. This paper attempts to provide such a new component by using Finite Element method using Basic Displacement Function (BDFs) for the free vibration ANALYSIS of plates with in-plane Functionally Graded Material (FGM). The first step is to introduce displacement functions and compute them using the energy method. Later, new shape functions are developed based on stiffness and force methods used to model the mechanical behavior of the element, wherein the shape functions benefit from the generality and accuracy of the stiffness and force methods. Last, the plate is analyzed using Finite Element method to derive the structural matrices from new shape functions. Several numerical examples demonstrate the accuracy and efficiency of the method, and a special material graded index named Ns is introduced.

In this study, distribution and tension concentration are analyzed in dowel joint. In current research, the effect of screw diameter are 4, 5 mm and type of woods are fugues oriental is, Alnus subcordata and white spruce on tension resistance and bending moment were tested. The dimensions for malting T-form joints were 5×5×2.5 wooden dowel used in this research was carpinus betulus which is the common dowel in malted. Also, Poly-vinyl acetate was used in Joints. The combination of above said factors in dowel joint 6 male totally 24 T sample by 4 repetitions and tension resistance and bending moment were measured by mechanical test machine. For exertion strength in order to analyze the aforementioned resistance, loading speed equal to 1.25 mm/min was used. Also, for analyzing the way of distribution and tension concentration in joint and changing process of tension base on changing the variables in this research finite element method and ANSYS Software were used. Based on the findings, the German modeling of joint which endures the maximum tension is equal to the type being used in real joints. Distribution of tension in the middle of the bending moment depths is maximum and tension in screw joints is consent Reid in failure Points.

In this study, distribution pattern and tension concentration as well as failure prediction in dowel joint were analyzed. The effect of dowel diameter (6, 8, 10 mm) and wood type (Beech, Alder and white spruce) on tension resistance and bending moment were examined. The dimensions for making T-form joints were 5×5×2.5 cm. Wooden dowel used in this research was carpinus betulus which accounts as the common dowel in market. Also, PVA was used in Joints. A total of 36 Tshape samples comprising 9 combinations of the above factors in 4 replications were made. Tension resistance and bending moment were measured by mechanical test machine. For exertion strength due to analyzing the resistance loading speed equal to 1.25 mm/min were applied. Also, to analyze distribution pattern and tension concentration in affected joints, finite element method and ANSYS Software were used. According to the results of the simulation modeling, joint which endured the maximum tension complied with the real joints. Distribution of tension in the middle of the bending moment depth was greatest and tension in dowel joints was concentrated in impaired points.

Low– velocity foreign object impact damage is one of the most important issues in composite materials used in military and civil structures. Fiber composites are strong sheets, which are subjected to impact loads, to reduce the damage of the impact using hard resins. In this research, low-speed bullet impact to six beams with FGM layering whose modulus of elasticity in the beam thickness varies from ceramic to metal and the response of the beams to low velocity impact has been investigated by finite element method using Abacus software. The strain, displacement and tension of the beam have been analyzed in two modes of the last layer of the metal and ceramic – metal. A comparison of displacement, tension and strain diagrams along the length of the beam for the six beams has been made. It was observed that the higher the properties of the metal than the ceramic, the higher the amount of displacement and tension and the strain in the beam decreased with increasing degree of ceramic properties compared to the metal.

Meanwhile damages on machine, the created vibrations during the machining process will effect on the significant results of the process, such as surface finishing.6ptimized design of the machine tool and high quality of the workpiece would be possible by determining the vibration characteristics of machine structure. In this paper, transient and harmonic dynamic behavior of gantry CNC milling machine (DMC 1000) has been studied. For this reason, rudimentary structure of the machine and its main complex are modeled in the commercial Solidworks software. Then, the natural frequency and dynamic response are evaluated in both transient and harmonic moods using ABAQUS.Finally, the stability condition is investigated for the current machine. Results showed that the system response is more sensitive under frequency of 400 Hz and the largest displacement occurs at first locating position of spindle.

Today, the rolled products, i.e. sheet, plate and foil is used in marine applications, including platforms, hatch covers, mast, hulls of boats and superstructures on pleasure boats and the bridges and superstructures of passenger ships and merchant ships. In this paper, simulation of asymmetric cold rolling is presented by using explicit ANALYSIS procedure. In asymmetric cold rolling, the workpiese if often bent downwards or upwards. A two dimensional explicit dynamic finite element model with adaptive meshing technique has been employed to simulate asymmetrical condition are here due to different roll radii. To validate the simulation, the results of simulation and experiment are compared. Effects of asymmetry due to roll radii ratio and speed ratio mismatch on sheet curvature variations are discussed. Finally, optimum roll speed ratio in various of roll radii ratio could be found to produce flat sheet.