scholarly journals Free Vibration Exploration of Rotating FGM Porosity Beams under Axial Load considering the Initial Geometrical Imperfection

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Nguyen Thi Giang
Keyword(s):  
Finite Element ◽  
Compressive Load ◽  
Shear Deformation Theory ◽  
Parameter Study ◽  
Compression Load ◽  
Large Structures ◽  
Geometrical Imperfection ◽  
Compressive Loads ◽  
Vibration Responses ◽  
Sine Functions

In practice, some components in large structures such as the connecting rods between the rotating parts in the engines, turbines, and so on, can model as beam structures rotating around the fixed axis and subject to the axial compression load; therefore, the study of mechanical behavior to these structures has a significant meaning in practice. This paper analyzes the vibration responses of rotating FGM beams subjected to axial compressive loads, in which the beam is resting on the two-parameter elastic foundation, taking into account the initial geometrical imperfection. Finite element formulations are established by using the new shear deformation theory type of hyperbolic sine functions and the finite element method. The materials are assumed to be varied smoothly in the thickness direction of the beam based on the power-law function with the porosity. Verification problems are conducted to evaluate the accuracy of the theory, proposed mechanical structures, and the calculation programs coded in the MATLAB environment. Then, a parameter study is carried to explore the effects of geometrical and material properties on the vibration behavior of FGM beams, especially the influences of the rotational speed and axial compressive load.

scholarly journals Study of Internal Response of Epoxy due to Compressive Load via Experiment and Simulation Using Abaqus FEA Software

2014 ◽  
Vol 896 ◽  
pp. 549-552 ◽  
Author(s):  
Irfan Dwi Aditya ◽  
Widayani ◽  
Sparisoma Viridi ◽  
Siti Nurul Khotimah
Keyword(s):  
Image Analysis ◽  
Polymer Matrix Composites ◽  
Matrix Material ◽  
Compressive Load ◽  
Polymeric Materials ◽  
Lateral Direction ◽  
Compression Load ◽  
Internal Response ◽  
Compressive Loads ◽  
Carbon Based

Epoxy is widely used primarily as a matrix material in the manufacture of Polymer Matrix Composites (PMC). Epoxy behavior under compression load has to be understood before the mechanical behavior of PMCs can be accurately predicted. Simulation model combined with experiment and image analysis are used to investigate internal response of epoxy resins polymeric materials subject to compressive loads. To investigate epoxy response to compressive load, small carbon-based material rods are inserted in the epoxy. The samples are held in one side and subjected to compressive load on the other side. All the samples swell at load sides. Image analysis on the carbon-based rods figures out the internal response, which seems to be isotropy in lateral direction. The results are compared to simulation results using Abaqus FEA. Similar condition is obtained when a brittle thin material is stuck to the top of the model.

Comparative Study of the Shock Resistance of Rubber Protective Coatings Subjected to Underwater Explosion

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Feng Xiao ◽  
Yong Chen ◽  
Hongxing Hua
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Protective Coatings ◽  
Dynamic Compression ◽  
Reaction Force ◽  
Compressive Load ◽  
Underwater Explosion ◽  
Finite Element Simulations ◽  
Compression Load ◽  
Shock Resistance

Finite element simulations of rubber protective coatings with different structures under two dynamic loading cases were performed. They were monolithic coating and honeycomb structures with three different cell topologies (hexachiral honeycomb, reentrant honeycomb, and circular honeycomb). The two loading cases were a dynamic compression load and water blast shock wave. The dynamic mechanical responses of those coatings under these two loading cases were compared. Finite element simulations have been undertaken using the ABAQUS/Explicit software package to provide insights into the coating's working mechanism and the relation between compression behavior and water blast shock resistance. The rubber materials were modeled as hyperelastic materials. The reaction force was selected as the major comparative criterion. It is concluded that when under dynamic compressive load, the cell topology played an important role at high speed, and when under underwater explosion, the honeycomb coatings can improve the shock resistance significantly at the initial stage. For honeycomb coatings with a given relative density, although structural absorbed energy has a significant contribution in the shock resistance, soft coating can significantly reduce the total incident impulse at the initial fluid-structure interaction stage. Further, a smaller fraction of incident impulse is imparted to the honeycomb coating with lower compressive strength.

Delamination Buckling of Composite Cylindrical Panels Under Axial Compressive Load

Volume 1 ◽  
2004 ◽  
Author(s):  
Tim Leigh ◽  
Azam Tafreshi
Keyword(s):  
Finite Element ◽  
Service Use ◽  
Computing Time ◽  
Compressive Load ◽  
Shear Deformation Theory ◽  
Local Mode ◽  
Global Mode ◽  
Local Modes ◽  
Cylindrical Panels ◽  
Delamination Buckling

Composite cylindrical shells and panels are widely used in aerospace structures. Delaminations within the composite structure reduce the compressive strength of laminates, and often result because of damage incurred during manufacturing and in-service use. This paper investigates the buckling behaviour of laminated cylindrical panels loaded in axial compression using the finite element method. The use of three-dimensional finite elements for predicting the delamination buckling of these structures is computationally expensive. Here the analysis has been carried out using a layerwise shell finite element based on the first-order, shear deformation theory. Contact elements were placed between the delaminated regions to avoid physical interpenetration of the elements. It is shown that through-the-thickness delamination can be modelled and analysed effectively without requiring a great deal of computing time and memory. Delamination shapes considered in this study were square and rectangular — extended longitudinally over the entire length or extended along the entire circumference of the panel. Some of the results were compared with the corresponding analytical results which were in good agreement. The most influential parameters for a given laminated panel were the size of the delamination and its through-the-thickness position. The effect of the curvature on the global buckling strength of a delaminated panel was also studied. Depending on the size and through the thickness position of delaminations, three different modes of buckling behaviour occur. The local mode occurs when the delamination is near the free surface of the laminate and the area of the delamination is large. The global mode occurs when the delamination is deeper within the laminate and has a small area. The mixed mode is a combination of global and local modes.

scholarly journals Finite Element Modeling for Static Bending Behaviors of Rotating FGM Porous Beams with Geometrical Imperfections Resting on Elastic Foundation and Subjected to Axial Compression

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Nguyen Van Dang
Keyword(s):  
Finite Element ◽  
Elastic Foundation ◽  
Shear Deformation Theory ◽  
Compressive Force ◽  
Power Law Distribution ◽  
Axial Compressive Force ◽  
Geometrical Imperfection ◽  
Geometrical Imperfections ◽  
Fixed Axis ◽  
Element Technique

The static bending analysis of the FG porous beam resting on the two-parameter elastic foundation is initially carried out using a combination of Reddy’s high-order shear deformation theory and the finite element technique, where the initial geometrical imperfection and rotation movement in one fixed axis are calculated. Through the power-law distribution function with porosities, material characteristics vary constantly from one surface to the next in the direction of thickness, and the beam is concurrently impacted by an acting force perpendicular to the beam axis and an axial compressive force. The stiffness matrix of the beam element changes as a result, and the static bending response of this beam is significantly different from that of ordinary beams. Comparison cases with published findings are used to verify the computational theory. The calculations clearly reveal many innovations for rotating beams that are influenced by many different kinds of loads, which may be used to the designing, manufacturing, and usage of these structures in reality.

scholarly journals Crushing Behavior of Thin-Walled Hexagonal Tubes with Partition Plates

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Dai-Heng Chen ◽  
Kenichi Masuda
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Axial Compression ◽  
Compressive Load ◽  
Full Length ◽  
Compression Load ◽  
Thin Walled Tube ◽  
Thin Walled ◽  
Crushing Behavior ◽  
Element Method

The crushing behaviour of hexagonal thin-walled tube with partition plates subjected to axial compression is studied by using finite element method. It is found that, in the crushing process, the folds, which generate along the full length of the tube, come to be crushed simultaneously and the compressive load will not descend, since the compressive load produced in the central part does not descend with the folds forming on outer walls. Therefore, in order to suppress a fluctuation of the compression load in crushing of the tube and to raise its average compression load, it is an effective method to introduce corner parts, especially corner parts where three plates intersect, in the geometry of the thin-walled tube.

Strength of Tubular Members Containing Holes

1994 ◽  
Vol 116 (3) ◽  
pp. 154-162 ◽  
Author(s):  
T. M. Hsu
Keyword(s):  
Finite Element ◽  
Ultimate Strength ◽  
Load Capacity ◽  
Compressive Load ◽  
Nonlinear Finite Element ◽  
Load Test ◽  
Small Scale ◽  
Hole Size ◽  
Compression Tests ◽  
Compression Load

A small-scale, compressive-load test program was conducted at Chevron to determine the strength of tubular members with 1 to 3 holes. The parameters evaluated include the hole size, hole shape, hole location, and number of holes. Results from these tests provide a basis for platform ultimate strength calculations that are needed in making decisions on platform repairs. More than 50 specimens were tested in air under displacment control. Test specimen lengths were limited by the test apparatus to 45 in. (1,143 mm). Tubulars used in the test had an outside diameter of 3.5 in. (89 mm), which gave member slenderness ratios of about 40. The tests were needed because of the lack of relevant compression tests on members with holes. Based on test results, there appears to be a limiting value of hole size below which the compression-load capacity of the member is practically not affected by the existence of the hole. For example, a hole that is 10 percent of the member diameter does not significantly reduce member strength. This means remedial treatment is not necessary for many small holes, when ultimate strength is the controlling consideration. Nonlinear finite element shell analyses using both ADINA and FACTS computer programs and a simplified analysis using DENTA-II PC program were performed and results compared with data. We found that nonlinear finite element programs provide good predictions of capacities of members with holes, and that a simplified DENTA-II program provides adequate and efficient predictions.

Finite element bending analysis of symmetric and non-symmetric functionally graded sandwich beams using a novel parabolic shear deformation theory

2021 ◽  
pp. 146442072110050
Author(s):  
Mohamed-Ouejdi Belarbi ◽  
Abdelhak Khechai ◽  
Aicha Bessaim ◽  
Mohammed-Sid-Ahmed Houari ◽  
Aman Garg ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Shear Deformation ◽  
Transverse Shear ◽  
Deformation Theory ◽  
Shear Deformation Theory ◽  
Element Model ◽  
Beam Element ◽  
Functionally Graded ◽  
Sandwich Beams

In this paper, the bending behavior of functionally graded single-layered, symmetric and non-symmetric sandwich beams is investigated according to a new higher order shear deformation theory. Based on this theory, a novel parabolic shear deformation function is developed and applied to investigate the bending response of sandwich beams with homogeneous hardcore and softcore. The present theory provides an accurate parabolic distribution of transverse shear stress across the thickness and satisfies the zero traction boundary conditions on the top and bottom surfaces of the functionally graded sandwich beam without using any shear correction factors. The governing equations derived herein are solved by employing the finite element method using a two-node beam element, developed for this purpose. The material properties of functionally graded sandwich beams are graded through the thickness according to the power-law distribution. The predictive capability of the proposed finite element model is demonstrated through illustrative examples. Four types of beam support, i.e. simply-simply, clamped-free, clamped–clamped, and clamped-simply, are used to study how the beam deflection and both axial and transverse shear stresses are affected by the variation of volume fraction index and beam length-to-height ratio. Results of the numerical analysis have been reported and compared with those available in the open literature to evaluate the accuracy and robustness of the proposed finite element model. The comparisons with other higher order shear deformation theories verify that the proposed beam element is accurate, presents fast rate of convergence to the reference results and it is also valid for both thin and thick functionally graded sandwich beams. Further, some new results are reported in the current study, which will serve as a benchmark for future research.

Nonlocal finite element model for the bending and buckling analysis of functionally graded nanobeams using a novel shear deformation theory

2021 ◽  
Vol 264 ◽  
pp. 113712 ◽  
Author(s):  
Mohamed-Ouejdi Belarbi ◽  
Mohammed-Sid-Ahmed Houari ◽  
Ahmed Amine Daikh ◽  
Aman Garg ◽  
Tarek Merzouki ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Shear Deformation ◽  
Deformation Theory ◽  
Shear Deformation Theory ◽  
Element Model ◽  
Buckling Analysis ◽  
Functionally Graded

scholarly journals Forced Vibration Analysis of Laminated Composite Shells Reinforced with Graphene Nanoplatelets Using Finite Element Method

2020 ◽  
Vol 2020 ◽  
pp. 1-17 ◽  
Author(s):  
Trung Thanh Tran ◽  
Van Ke Tran ◽  
Pham Binh Le ◽  
Van Minh Phung ◽  
Van Thom Do ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Forced Vibration ◽  
Vibration Analysis ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Thermal Environments ◽  
Forced Vibration Analysis ◽  
Laminated Composite Shells ◽  
Element Method

This paper carries out forced vibration analysis of graphene nanoplatelet-reinforced composite laminated shells in thermal environments by employing the finite element method (FEM). Material properties including elastic modulus, specific gravity, and Poisson’s ratio are determined according to the Halpin–Tsai model. The first-order shear deformation theory (FSDT), which is based on the 8-node isoparametric element to establish the oscillation equation of shell structure, is employed in this work. We then code the computing program in the MATLAB application and examine the verification of convergence rate and reliability of the program by comparing the data of present work with those of other exact solutions. The effects of both geometric parameters and mechanical properties of materials on the forced vibration of the structure are investigated.

scholarly journals New Evaluation Procedure for Multi-Dimensional Mechanical Strains and Tangent Moduli of Breast Implants: IDEAL IMPLANT® Structured Breast Implant Compared to Silicone Gel Implants

2019 ◽  
Vol 6 (2) ◽  
pp. 43 ◽  
Author(s):  
Harold J. Brandon ◽  
Larry S. Nichter ◽  
Dwight D. Back
Keyword(s):  
Breast Implant ◽  
Capsular Contracture ◽  
Compressive Load ◽  
Evaluation Procedure ◽  
Shape Stability ◽  
Silicone Gel ◽  
Tangent Moduli ◽  
Compressive Loads ◽  
Cohesive Gel ◽  
The Ideal

The IDEAL IMPLANT® Structured Breast Implant is a dual lumen saline-filled implant with capsular contracture and deflation/rupture rates much lower than single-lumen silicone gel-filled implants. To better understand the implant’s mechanical properties and to provide a potential explanation for these eight-year clinical results, a novel approach to compressive load testing was employed. Multi-dimensional strains and tangent moduli, metrics describing the shape stability of the total implant, were derived from the experimental load and platen spacing data. The IDEAL IMPLANT was found to have projection, diametric, and areal strains that were generally less than silicone gel implants, and tangent moduli that were generally greater than silicone gel implants. Despite having a relatively inviscid saline fill, the IDEAL IMPLANT was found to be more shape stable compared to gel implants, which implies potentially less interaction with the capsule wall when the implant is subjected to compressive loads. Under compressive loads, the shape stability of a higher cross-link density, cohesive gel implant was unexpectedly found to be similar to or the same as a gel implant. In localized diametric compression testing, the IDEAL IMPLANT was found to have a palpability similar to a gel implant, but softer than a cohesive gel implant.

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