Development of analytical orbit propagation technique with drag

Two orbit computation methods were used: (1) numerical method- The solution to the satellite differential equations were solved in a step-by-step manner, using a mathematical algorithm taken from numerical analysis; and (2) analytical method - The solution was expressed by explicit functions of the independent variable. Analytical drag modules, tesseral terms initialization module, second order and long period terms module, and verification testing of the ASOP program were also considered

Towards a novel design method for impact on leading edges

Results of a parametric study concerning low velocity impact on leading edge profiles is presented. This work is the first part of a larger program on the development of an engineering design method for impact on Glare. In this first part, experimental tests and numerical simulations on two-dimensional aluminium leading edge profiles were carried out. An extensive parametric study was done using numerical analysis. Selected configurations have been validated using impact tower testing. Impact tests were done with a solid impactor with a circular diameter on leading edges having a width of 20 mm. Profiles with three different thicknesses and three different sizes were tested. Impact velocities were in the range 1 to 8 m/s. The numerical models predicted the deformation of the leading edges accurately. Important impact parameters were identified and relations were established between impact parameters and geometrical properties of the leading edge profiles. The obtained results give important insight in the set up of simulations and experimentation and in the identification of important parameters of leading edge impact

Analisis Karakteristik Akustik Dan Dinamik Micro-Perforated Panel Dengan Struktur Honeycomb Mengunakan FEM

This study focuses on the discussion of the correlation of acoustic and dynamic characteristics of hybrid panels, namely Micro-perforated Panel (MPP) and Honeycomb (HC) structures. Acoustic characteristics in experimental studies are obtained by the sound absorption coefficient and Sound Transmission Loss. Meanwhile, the dynamic characteristics are obtained by the mode and frequency response analysis of numerical simulation methods. The results of these two characteristics serve as a benchmark for the development of experimental data studies/analysis. The purpose of this study is to obtain dynamic characteristics using mode and frequency response analysis through the finite element method. The development of this experimental study/analysis data is to overcome the drawbacks of experimental testing. The weakness obtained from experimental studies is that the stages are complicated and require a very large amount of money. The method in this study was carried out by numerical simulation using the finite element method using the Ansys 2019 R3 program. The results of this study obtained dynamic characteristics from the development of experimental study analysis methods using numerical simulations through the finite element method. Numerical simulation on the hybrid panel provides efficiency at the experimental testing stage. The results of the mode and frequency response analysis obtained by numerical simulation methods have similarities in the frequency range of high and low frequency values of sound absorption coefficient and soundtransmission loss

Experimental and numerical studies on multi-spherical sliding friction isolation bearing

An innovative multi-spherical sliding friction isolation (MSFI) bearing has recently been developed. The novel isolator has efficient energy dissipation capacity and enough displacement capacity under strong earthquake excitations. The MSFI bearing is completely passive devices, yet shows smart stiffness and smart damping under external excitation. The principles of operation and force-displacement relationship of the novel isolator are presented in this paper. The sliding order of all sliding surfaces and force-displacement hysteretic relationship are verified through a displacement-control testing program, and numerical analysis of the MSFI bearing under low cyclic loading is carried out based on ABAQUS program. The results show the sliding order and force-displacement relationship of the MSFI bearing derived from theoretical analysis results and numerical simulation results are well agree with experimental data which the compression-shear testing of the MSFI bearing specimen with the identical curvature radii and friction coefficients. The adaptive behavior of MSFI bearing permits the isolation system to be separately optimized for multiple levels of seismic intensity and ground motions

DEM Simulation Based on Experimental Testing

The paper examines several key aspects of soil morphology, namely experimental and numerical test validation and compression test result dependency on changing morphology parameters. The present chapter describes investigation of soil morphology parameters influence for numerical compression properties with evaluation of examined sand engineering geological conditions. The main objects of research: morphology parameters investigation with view analysis program and scanning electronic microscope; experimental soil compression testing; numerical soil compression simulation and results validation with experimental ones. The primary purpose of this paper is therefore to investigate the influence of morphology parameters on sand mechanical properties and to determine optimal quantity of spheres for single‐particle shape subscription

On numerically accurate finite element

A general criterion for testing a mesh with topologically similar repeat units is given, and the analysis shows that only a few conventional element types and arrangements are, or can be made suitable for computations in the fully plastic range. Further, a new variational principle, which can easily and simply be incorporated into an existing finite element program, is presented. This allows accurate computations to be made even for element designs that would not normally be suitable. Numerical results are given for three plane strain problems, namely pure bending of a beam, a thick-walled tube under pressure, and a deep double edge cracked tensile specimen. The effects of various element designs and of the new variational procedure are illustrated. Elastic-plastic computation at finite strain are discussed

Application of the p-version of the finite-element method to global-local problems

A brief survey is given of some recent developments in finite-element analysis technology which bear upon the three main research areas under consideration in this workshop: (1) analysis methods; (2) software testing and quality assurance; and (3) parallel processing. The variational principle incorporated in a finite-element computer program, together with a particular set of input data, determines the exact solution corresponding to that input data. Most finite-element analysis computer programs are based on the principle of virtual work. In the following, researchers consider only programs based on the principle of virtual work and denote the exact displacement vector field corresponding to some specific set of input data by vector u(EX). The exact solution vector u(EX) is independent of the design of the mesh or the choice of elements. Except for very simple problems, or specially constructed test problems, vector u(EX) is not known. Researchers perform a finite-element analysis (or any other numerical analysis) because they wish to make conclusions concerning the response of a physical system to certain imposed conditions, as if vector u(EX) were known