Static Deformation Analysis Research Articles

STATIC DEFORMATION ANALYSIS OF A MOBILE CUTTING MACHINE

A study of the special requirements and criteria to portable cutting machines was carried out. Based on the existing approaches to the deformation analysis of spindle units the calculation schemes and mathematical model for the static analysis of the problem were developed. The implemented approach makes use of the Timoshenko beam model. The resulting differential equation of the bent beam axis is solved by the method of initial parameters in the matrix form. The nonlinear equation system for the chosen calculation scheme is formed automatically and is solved iteratively. A special feature of the proposed approach is the nonlinear relation between the stiffness of the bearings and the forces acting upon them. As a model application example, the results of the static deformation analysis of portable boring machine XT7809-0524 are presented. An estimate of the bending stiffness and the corresponding distributions of bending deflections and rotations were obtained for several calculation schemes of the machine. The obtained solution quantities are presented in form of graphs along the spindle axis. It has been found, that the calculated equivalent stiffness of XT7809-0524 machine spindle shaft is lower than the normative value used in the industry. A strength assessment of the spindle shaft was also made and the distributions of internal forces and moments acting on shaft cross sections were obtained. It has been concluded, that under work loads the maximum stress in the shaft is acceptable to provide for the required factor of safety.

Design and Analysis of a High-Precision Horizontal Machine Tools

Abstract: The horizontal machine tool has an automatic exchange table, which can be combined with a flexible manufacturing system for automatic processing and production. Therefore, it requires higher performance stability than other machines. This study analyzes the static and dynamic characteristics of a horizontal machine tool structure. The finite element analysis (FEA) method is generally used to analyze the whole machine structure and improve the deformation and resonance of the horizontal machine tool. In this study, FEA was applied to the design process of the machine tool, including static deformation analysis, modal analysis, transient analysis, and harmonic analysis of the machine. The deformation of the whole machine due to acceleration of gravity and cutting force was analyzed. The modal shapes generated by the first and third modes directly affected the machining process of the machine tool. To further analyze the influence of vibration signal processing on processing quality, transient response analysis was carried out on the effect of axial cutting force during machining. Spectrum analysis of the machine was also carried out. This study is expected to help the structural design of a horizontal machine tool to improve the dynamic characteristics and stability of the horizontal machining system.

A new sandwich beam model with layer-to-layer boundary modified displacements based on higher-order absolute nodal coordinate formulation

The absolute nodal coordinate formulation (ANCF) is one of the efficient modeling methods to solve the dynamics of flexible multibody systems. Zig-zag theory can accurately calculate the stress variation in the sandwich structure with only a few unknown variables, thus providing a good balance between computational efficiency and computational accuracy. Combining ANCF and zig-zag theory, this paper proposes a new sandwich beam model, called HANCF-ZZ, by introducing layer-to-layer boundary modified displacements in a high-order ANCF beam model. The capability of HANCF-ZZ for static deformation analysis and free vibration analysis is verified by comparing experimental, analytical, and numerical results in other literature. The results show that the HANCF-ZZ corrects the global stiffness overestimated by the equivalent single-layer theory, eliminates the locking problem of the low-order ANCF, and captures the nonlinear bifurcation phenomenon in large deformation problems under large loads. The HANCF-ZZ is not only an efficient numerical method for zig-zag theory but also enriches the ANCF element types to enable its application to the dynamics analysis of soft core sandwich beams.

On the deformation of laminated composite and sandwich curved beams

Abstract Plenty of research articles are available on the static deformation analysis of laminated straight beams using refined shear deformation theories. However, research on the deformation of laminated curved beams with simply supported boundary conditions is limited and needs more attention nowadays. With this objective, the present study deals with the static analysis of laminated composite and sandwich beams curved in elevation using a new quasi-3D polynomial type beam theory. The theory considers the effects of both transverse shear and normal strains, i.e. thickness stretching effects. In the present theory, axial displacement has expanded up to the fifth-order polynomial in terms of thickness coordinates to effectively account for the effects of curvature and deformations. The present theory satisfies the zero traction boundary condition on the top and bottom surfaces of the beam. Governing differential equations and associated boundary conditions are established by using the Principal of virtual work. Navier’s solution technique is used to obtain displacements and stresses for simply supported beams curved in elevation and subjected to uniformly distributed load. The present results can be benefited to the upcoming researchers.

Spatial Data Analysis for Deformation Monitoring of Bridge Structures

Weather conditions and different operational loads often cause changes in essential parts of engineering structures, and this affects the static and dynamic behavior and reliability of these structures. Therefore, geodetic monitoring is an integral part of the diagnosis of engineering structures and provides essential information about the current state (condition) of the structure. The development of measuring instruments enables deformation analyses of engineering structures using non-conventional surveying methods. Nowadays, one of the most effective techniques for spatial data collection is terrestrial laser scanning (TLS). TLS is frequently used for data acquisition in cases where three-dimensional (3D) data with high resolution is needed. Using suitable data processing, TLS can be used for static deformation analysis of the structure being monitored. For dynamic deformation measurements (structural health monitoring) of bridge structures, ground-based radar interferometry and accelerometers are often used for vibration mode determination using spectral analysis of frequencies. This paper describes experimental deformation monitoring of structures performed using TLS and ground-based radar interferometry. The procedure of measurement, the analysis of the acquired spatial data, and the results of deformation monitoring are explained and described.

3D syndiotactic elastic metastructure with single-phase material

The artificially periodic structures with the bandgap (BG) features provide a fantastic way for elastic wave manipulation. However, omnidirectional control of elastic waves at low-frequency remains a challenge, especially in the engineering application, due to the great different material parameters of the structure's components. In this work, we present the design of a three-dimensional syndiotactic metastructure (STM) and isotactic metastructure (ITM) composed of a single material with the same density and stiffness. A low-frequency broad bandgap occurs in the global band structure of STM. Meanwhile, it also retains the same high-frequency ultra-wide BG as that of ITM. The formation of the low-frequency BG of STM is attributed to the simultaneous activation of rotation and translation modes. The static deformation analysis indicates that STM has a unique translational and rotational coupling mechanism. The frequency response results reveal that the coupling mechanism can also enhance the attenuation of high-frequency BG.

Development of mathematical models for calculating statics and dynamics of membrane sensitive elements of microelectromechanical control systems

The article is devoted to the development of mathematical models for calculating the statics and dynamics of membrane sensitive elements of microelectromechanical control systems. The nonlinear analysis of membrane sensitive elements and the finite element method are considered. The analysis of various options for membrane elastic sensitive elements of pressure sensors and their theoretical models. The method of numerical simulation, the method of linear analysis of static deformation and the comparison of the results of a theoretical calculation of the deformation profiles with experimental values are used. A method for calculating statics and dynamics, membrane and beam microelectromechanical control systems provides a high degree of adequacy with real stress-strain states in the structures of membrane and beam elastic microelectromechanical control systems, as well as reducing the complexity of engineering calculations.

New deformation prediction of micro thin-walled structures by iterative FEM

The machining of micro thin-walled parts constitutes a key process in the microelectronic field. Deformations and machining errors easily occur, due to the low stiffness of micro thin walls. In this paper, a new iterative finite element method (iterative FEM) was proposed for the deformation predictions based on previous conducted works in the authors’ laboratory. The new method, with aim at the effect of low radial immersion milling, was improved in three aspects compared to the traditional predicted methods: interaction calculation between the deformation extent and the cutting force; the grid division was significantly intensive; the cutting force was dispersed on certain nodes similarly to real cases. Firstly, the static deformation analysis and iterative FEM were introduced. Following, a diamond-coated micro milling tool was utilized to machine the micro thin-walled structures of 30 to 105 μm in thicknesses. Subsequently, several tungsten steel-coated milling tools were also utilized. Various tool diameters and edge radii were selected for comparison to the diamond-coated micro milling tool. The experimental results demonstrated that the deformations were approximately consistent with the simulation results, although certain errors still existed.

Parameter Variations of Identified Model for Static Deformation Analysis of Arch Dam

Parameter Variations of Identified Model for Static Deformation Analysis of Arch Dam

A new crank arm based load cell, with built-in conditioning circuit and strain gages, to measure the components of the force applied by a cyclist.

This report describes the development of a force platform based on instrumented load cells with built-in conditioning circuit and strain gages to measure and acquire the components of the force that is applied to the bike crank arm during pedaling in real conditions, and save them on a SD Card. To accomplish that, a complete new crank arm 3D solid model was developed in the SolidWorks, with dimensions equivalent to a commercial crank set and compatible with a conventional road bike, but with a compartment to support all the electronics necessary to measure 3 components of the force applied to the pedal during pedaling. After that, a 6082 T6 Aluminum Crankset based on the solid model was made and instrumented with three Wheatstone bridges each. The signals were conditioned on a printed circuit board, made on SMD technology, and acquired using a microcontroller with a DAC. Static deformation analysis showed a linearity error below 0.6% for all six channels. Dynamic analysis showed a natural frequency above 136Hz. A one-factor experiment design was performed with 5 amateur cyclists. ANOVA showed that the cyclist weight causes significant variation on the force applied to the bicycle pedal and its bilateral symmetry.

The March–April 2014 sequence of earthquakes in North Chile

During March–April 2014 a series of earthquakes occurred around the Iquique city located in the northern Chile region. The two largest events of this sequence are the Mw8.2, April 1, 2014 and Mw7.7, April 4, 2014 quakes. Here we computed the nodal planes of eight of the large and well teleseismically recorded events of this series based on grid search, teleseismic moment tensors inversion, empirical Green's function deconvolution and its stack to average the deconvolutions for the Mw = 8.2, April 1, 2014, synthetic Green's function deconvolution and its stack to average the deconvolutions for the same event and 3D static deformation analysis of the above mentioned events based on the AK135 model. Grid search nodal planes and moment tensors suggest the dominance of reverse faulting. Almost all of the calculated teleseismic moment tensors represent a considerable amount of DC (usually more than 90%) and lower amount of CLVD for this sequence of events. Empirical and synthetic Green's function deconvolution showing down dip rupture propagation and 3D static deformation representing higher amount of vertical deformation in comparison with horizontal deformation components plus the existence of uplift and subsidence. According to the aftershocks distribution there is a bilateral distribution of the aftershocks around the first large event of this sequence that occurred March 16, 2014 (Mw6.7) so that they are approximately limited between the Mw8.2 (at north) and Mw7.7 (at south) quakes. Moreover there exist two bands of regional seismicity during early-mid 2014: a shallow off-shore band between the trench and coast and a deeper inland band under the active volcanic chain (both nearly parallel to the trench).

Finite Element Static Deformation Analysis of the Cylinder

In this paper, finite element static deformation analysis of the cylinder was carried out by Pro/E and ANSYS Workbench software. The deformation contours of the cylinder were obtained. By means of the contours, deep research about deformation distribution condition and the maximum deformation concentration parts of cylinder mechanism were conducted. The research is helpful for the improvement of the structure and the subsequent optimization of cylinder mechanism.

A Measure to Imitate the Boundary Condition of Local Structure in Modal Analysis

The static element in static deformation analysis was used to simulate the boundary condition of local structure when studying the modality of local structure. Using this method, the vibration modality of a beam system and the main engine lubricating oil tank were researched. The results show that the usage of static element in dynamic analysis can solve the vibration modality of local structure accurately, the difference ratio of first order frequency is less than 1/10000 in the beam model analysis, and the modal analysis of main engine lubrication oil tank has a good performance, which is a helpful base for the coupling vibration research in ship structure.

Complex 3-D Finite Element modelling of the 2009 April 6 L’Aquila earthquake by inverse analysis of static deformation

SUMMARY On 2009 April 6 a Mw = 6.3 earthquake struck the Abruzzi region (Central Italy) and caused severe destruction in L’Aquila and the surrounding area. In this work we present a Finite Element analysis of the event based on a realistic complex 3-D model, accounting for topographic relief and rheological heterogeneities deduced from local tomography. Finite Element computed Green's functions were implemented in a linear inversion of GPS coseismic displacements, to retrieve the slip distribution on the rupture plane. The inverted slip models basically agree with previous studies carried out on homogeneous domains, but reveal the presence of a single high slip patch, whereas half-space or 1-D approaches obtain a more complex slip pattern. Our results point out that the introduction of 3-D features significantly influences the obtained source model, suggesting a trade-off between domain complexities and source details.

Radial basis functions collocation and a unified formulation for bending, vibration and buckling analysis of laminated plates, according to a variation of Murakami’s zig-zag theory

In this paper, we propose a variation of the use of Murakami’s zig-zag theory for the analysis of laminated plates. The new theory accounts for through-the-thickness deformation, by considering a quadratic evolution of the transverse displacement with the thickness coordinate. The equations of motion and the boundary conditions are obtained by the Carrera’s Unified Formulation, and further interpolated by collocation with radial basis functions . This paper considers the analysis of static deformations, free vibrations and buckling loads on laminated composite plates .

Radial basis functions–finite differences collocation and a Unified Formulation for bending, vibration and buckling analysis of laminated plates, according to Murakami’s zig-zag theory

In this paper, we propose to use the Murakami’s zig-zag theory for the static and vibration analysis of laminated plates, by local collocation with radial basis functions in a finite differences framework. The equations of motion and the boundary conditions are obtained by the Carrera’s Unified Formulation, and further interpolated by a local collocation with radial basis functions and finite differences. This paper considers the analysis of static deformations, free vibrations and buckling loads on laminated composite plates.

Kinematic landslide monitoring with Kalman filtering

Abstract. Landslides are serious geologic disasters that threat human life and property in every country. In addition, landslides are one of the most important natural phenomena, which directly or indirectly affect countries' economy. Turkey is also the country that is under the threat of landslides. Landslides frequently occur in all of the Black Sea region as well as in many parts of Marmara, East Anatolia, and Mediterranean regions. Since these landslides resulted in destruction, they are ranked as the second important natural phenomenon that comes after earthquake in Turkey. In recent years several landslides happened after heavy rains and the resulting floods. This makes the landslide monitoring and mitigation techniques an important study subject for the related professional disciplines in Turkey. The investigations on surface deformations are conducted to define the boundaries of the landslide, size, level of activity and direction(s) of the movement, and to determine individual moving blocks of the main slide. This study focuses on the use of a kinematic deformation analysis based on Kalman Filtering at a landslide area near Istanbul. Kinematic deformation analysis has been applied in a landslide area, which is located to the north of Istanbul city. Positional data were collected using GPS technique. As part of the study, conventional static deformation analysis methodology has also been applied on the same data. The results and comparisons are discussed in this paper.

Analysis of Functionally Graded Plates by a Robust Meshless Method

The analysis of static deformations of functionally graded plates is performed by using the collocation method, the radial basis functions and a higher-order shear deformation theory. The collocation method is truly meshless, allowing a fast and simple domain and boundary discretization. We select the shape parameter in the radial basis functions by an optimization procedure based on the cross-validation technique, and use the Mori-Tanaka homogenization technique to deduce effective properties of functionally graded materials. Numerical tests show that the method is reliable, robust and produces accurate results.

Nonlinear Anisotropic Stress Analysis of Anatomically Realistic Cerebral Aneurysms

Static deformation analysis and estimation of wall stress distribution of patient-specific cerebral aneurysms can provide useful insights into the disease process and rupture. The three-dimensional geometry of saccular cerebral aneurysms from 27 patients (18 unruptured and nine ruptured) was reconstructed based on computer tomography angiography images. The aneurysm wall tissue was modeled using a nonlinear, anisotropic, hyperelastic material model (Fung-type) which was incorporated in a user subroutine in ABAQUS. Effective material fiber orientations were assumed to align with principal surface curvatures. Static deformation of the aneurysm models were simulated assuming uniform wall thickness and internal pressure load of 100 mm Hg. The numerical analysis technique was validated by quantitative comparisons to results in the literature. For the patient-specific models, in-plane stresses in the aneurysm wall along both the stiff and weak fiber directions showed significant regional variations with the former being higher. The spatial maximum of stress ranged from as low as 0.30 MPa in a small aneurysm to as high as 1.06 MPa in a giant aneurysm. The patterns of distribution of stress, strain, and surface curvature were found to be similar. Sensitivity analyses showed that the computed stress is mesh independent and not very sensitive to reasonable perturbations in model parameters, and the curvature-based criteria for fiber orientations tend to minimize the total elastic strain energy in the aneurysms wall. Within this small study population, there were no statistically significant differences in the spatial means and maximums of stress and strain values between the ruptured and unruptured groups. However, the ratios between the stress components in the stiff and weak fiber directions were significantly higher in the ruptured group than those in the unruptured group. A methodology for nonlinear, anisotropic static deformation analysis of geometrically realistic aneurysms was developed, which can be used for a more accurate estimation of the stresses and strains than previous methods and to facilitate prospective studies on the role of stress in aneurysm rupture.

Analysis of Static Deformation, Vibration and Active Damping of Cylindrical Composite Shells with Piezoelectric Shear Actuators

An analytical solution is presented for the static deformation and steady-state vibration of simply supported hybrid cylindrical shells consisting of fiber-reinforced layers with embedded piezoelectric shear sensors and actuators. The piezoelectric shear actuator, which is poled in the circumferential direction, will induce transverse shear deformation of the hybrid shell when it is subjected to an electric field in the radial direction. Suitable displacement and electric potential functions that identically satisfy the boundary conditions at the simply supported edges are used to reduce the governing equations of static deformation and steady-state vibrations of the hybrid laminate to a set of coupled ordinary differential equations in the radial coordinate, which are solved by employing the Frobenius method. Natural frequencies, mode shapes, displacements, electric potential, and stresses are presented for four-layer hybrid laminates consisting of a piezoelectric shear sensor and actuator sandwiched between fiber-reinforced composite layers. Active vibration damping is implemented using a positive position feedback controller. Frequency response curves for different controller frequencies, controller damping ratio, and feedback gain demonstrate that the embedded shear actuator can be used for active damping of the fundamental flexural mode. In addition, it is demonstrated that vibration suppression of thickness modes is also feasible using the piezoelectric shear actuator.