Plastic Deformation of Steel Safety Guardrails

2001 ◽  
Author(s):  
Detlef Neuenhaus ◽  
Christian Kammel ◽  
Urs Joachim Geßler ◽  
Gerhard Sedlacek
Keyword(s):  
Multibody Systems ◽  
Tangential Direction ◽  
Normal Direction ◽  
Virtual Power ◽  
Program Code ◽  
Contact Zones ◽  
Vehicle Impact ◽  
Common Plane ◽  
The Common ◽  
Sophisticated Algorithm

Abstract In case of contact between two colliding bodies various force interactions in the contact area occur. Therefore, the virtual power for contact zones has to comprise impulse or contact in normal direction and friction in tangential direction of the common plane depending on the way of relative movement. Within this paper a sophisticated algorithm for the description of the virtual power in contact zones is presented. Hence, the implementation of this algorithm to the MEPHISTO (Multibody systems with ElasticPlastic HInges and changeable STructure Organization) multibody program code is successfully proved in the particular case of vehicle impact on a safety barrier system.

scholarly journals On the relations between systems of curves which, together, cut their plane into squares

1888 ◽  
Vol 7 ◽  
pp. 2-3
Author(s):  
Tait
Keyword(s):  
Unit Vector ◽  
Common Plane ◽  
The Common ◽  
Image Position

If ρ be the vector of a corner of a square in one system, σ that in a system derived without inversion, we must obviously havek being the unit-vector perpendicular to the common plane.

scholarly journals Tracing Transit (in)Tensions Between Settler Colonized ECE Contact Zones

2019 ◽  
pp. 69-81
Author(s):  
Sherri-Lynn Yazbeck ◽  
Miriam Brown ◽  
Ildikó Danis ◽  
Narda Nelson
Keyword(s):  
British Columbia ◽  
Contact Zone ◽  
Settler Colonialism ◽  
Contact Zones ◽  
Childcare Centre ◽  
The Common

Tracing the curiosity of children, educators, and researchers at a childcare centre in Melbourne, Australia and Victoria, British Columbia, Canada, we wonder how we might connect digitally across continents while thinking with place-specific encounters and tensions. In this article we share stories and unexpected (in)tensions that arise during a FaceTiming inquiry to invite questions that unsettle sedimented notions of who and what belongs inthe colonized places in which our settler educator practices take place. Provoked by Donna Haraway’s SF string figure method and situating our work within a common worlds framework, we seek new ways of connecting and transiting between our respective contact zones. In this article, we follow and pull at unsettling threads with the giving and receiving of two puppets, Bunjil and Waa, as they travel from their home in the Australian settler contact zone to the hands of those in the Canadian settler contact zone. These practices trace how these woven threads presence transit (in)tensions continue to stretch our thinking and modes of participating in our attempts at becoming accountable within the common worlds and our stories. How might this messy work make visible our accountabilities and inheritances in places of ongoing settler colonialism?

Sequential design of two orthogonal dynamic vibration absorbers in a pendulum based on stability maximization

2012 ◽  
Vol 226 (11) ◽  
pp. 2645-2655 ◽  
Author(s):  
LD Viet
Keyword(s):  
Tangential Direction ◽  
Normal Direction ◽  
Vibration Absorber ◽  
Vibration Absorbers ◽  
Dynamic Vibration Absorber ◽  
Linear Dynamic ◽  
Dynamic Vibration ◽  
Dynamic Vibration Absorbers ◽  
Small Benefit ◽  
The Stability

A dynamic vibration absorber moving in the tangential or in the normal direction of a pendulum’s orbit can reduce the free vibration of the pendulum. This article discusses the problem of a pendulum structure attached with two dynamic vibration absorbers moving orthogonally at the same time. The analytical optimization is proposed to be done in two steps, in which the parameters of the linear dynamic vibration absorber moving in tangential direction and the non-linear dynamic vibration absorber moving in normal direction are chosen sequentially based on the stability maximization criterion. The analytical analysis shows that the two-dynamic vibration absorber scheme has small benefit in comparison with the single-dynamic vibration absorber scheme. The analytical conclusions are verified by numerical calculations. Although the conclusion of the article is unexpected, it is important in practice because the two-dynamic vibration absorber arrangement can be excluded in the design.

Image stitching for construction of seabed mosaics

2018 ◽  
Author(s):  
А.Н. Камаев ◽  
С.И. Смагин
Keyword(s):  
3D Model ◽  
Small Distance ◽  
Image Stitching ◽  
Bottom Relief ◽  
Simple Method ◽  
Common Plane ◽  
Graphic Accelerator ◽  
Section Model ◽  
The Common ◽  
Color Blending

Решается задача сшивки фотографических изображений при построении карт морского дна на основе известных положений и ориентаций камеры автономного необитаемого подводного аппарата и расположения характерных (особых) точек на дне. Рассматриваются два алгоритма: простая сшивка, когда участок дна, видимый на каждом изображении, аппроксимируется плоскостью, и сшивка на основе трехмерной модели дна. Purpose. Seabed mosaics are built of tens of thousands of images obtained by the AUV at a small distance from the bottom. The height of the survey is limited by the power of the AUV lighting equipment and the transparency of the water and is often comparable with the differences in the heights of the bottom. This leads to strong distortions caused by parallax, which makes standard stitching methods inapplicable to the construction of photographic maps of the bottom with a complex relief. Methodology. The article proposes to consider the problem of constructing seabed mosaics as a problem of 3D reconstruction. Two approaches to stitching images are described: simple stitching and based on a 3D bottom model. With simple stitching, the relief represented by each image is approximated by a plane that is then projected onto the common plane of the seabed mosaic. When stitching based on a 3D model, the bottom section model is first constructed using the Delaunay triangulation, and then each triangle of the model is projected onto the plane of the map using a graphic accelerator GPU. To mix colors, a simple method of weighting the pixels of images is used, depending on their distance from the edges of the image. Findings. Stitching algorithms proposed in the paper were tested on images obtained by both real AUV and synthetic images. This allowed us to verify efficiency of stitching algorithms for conditions of a highly complex relief. In combination with simple color blending techniques, proposed algorithms have shown their practical efficiency. The stitching algorithm, based on the 3D model demonstrated its robustness to distortions caused by parallax. Originality/value. The main advantage of described approach is an absence of necessity to use computationally consuming, nontrivial color blending techniques while constructing seabed mosaics in the case of complex bottom relief.

Simple graphical methods for estimating the confidence region about the orientation of the intersection of two planes

1978 ◽  
Vol 15 (10) ◽  
pp. 1598-1604 ◽  
Author(s):  
D. Cruden ◽  
D. Kelker
Keyword(s):  
Structural Geology ◽  
Rock Mechanics ◽  
Graphical Method ◽  
Confidence Region ◽  
Acute Angle ◽  
Graphical Methods ◽  
Graphical Construction ◽  
Large Size ◽  
Common Plane ◽  
The Common

We give a simple graphical method for the construction on a stereonet of the confidence region for the orientation of the line of intersection of two planes. The method applies when the poles to the planes have been estimated by large and approximately equal numbers of measurements which may be treated as samples from two Fisher distributions of equal and large precision parameters. The method requires the estimation of the acute angle between poles to the planes and the range of the plunges of the poles.When the samples of poles are samples of large size from two Bingham distributions tightly clustered about their common plane, a more complex graphical construction is available. It requires the estimation of scatter of the poles in and perpendicular to the common plane and some simple calculations.The methods are applicable to a variety of problems in structural geology and rock mechanics.

Stability Analysis for Bedded Rock Slope with Effect of Contact

2012 ◽  
Vol 446-449 ◽  
pp. 1791-1796
Author(s):  
Xu Dong Li ◽  
Chao Su
Keyword(s):  
Rock Slope ◽  
Calculation Model ◽  
Structure Stability ◽  
Rock Slopes ◽  
Safety Factors ◽  
Common Plane ◽  
The Common ◽  
Dip Angle ◽  
Bedded Rock ◽  
The Mathematical Model

Structure stability of bedded rock slopes are determined by material characteristic of rock blocks and geometrical non-linearity of the discontinuous interfaces between the rock blocks. Different dip angle of the similar slopes are with different safety factors. In this paper, the discrete element method is adopted for calculation and the common plane method for contact surface searched, and the mathematical model is reviewed. Both states of calculation mode are adopted to analysis and compare, one considers the material elastic-plasticity of blocks of rock slope only, in the contrast, the other introduces the geometrical non-linearity to calculation model and the safety factor is less than the counterpart of first state.

Analysis of Machining Disturbance and Development of a Support System for the Finishing Process

2009 ◽  
Author(s):  
Daiki Sakito ◽  
Yasushi Yasuda ◽  
Tsuginobu Osada ◽  
Ken’ichi Yano
Keyword(s):  
Contact Force ◽  
Support System ◽  
Control Method ◽  
Force Sensor ◽  
Tangential Direction ◽  
Friction Torque ◽  
Normal Direction ◽  
Haptic Device ◽  
Sensor Output ◽  
Finishing Process

In this paper we address the development of a finish machining support system that can operate without machining mistakes for the limited production of diversified products. The machining is supported by a haptic device. One challenge is that it is necessary to separate the force sensor output that exists in the operation force from the machining influence force. We propose a control method to remove the influence of the rotation tool disturbance force from the operation force by using adaptive modeling, which estimates the force of rotation tool friction torque in the tangential direction of the machining side from the contact force in the normal direction of the machining side. The effectiveness of this research is shown by a machining experiment.

Linear Complementary Formulations Involving Frictional Contact for Elasto-Plastic Deformable Bodies

1997 ◽  
Vol 64 (1) ◽  
pp. 80-89 ◽  
Author(s):  
Maocheng Li ◽  
Desong Sha ◽  
K. K. Tamma
Keyword(s):  
Frictional Contact ◽  
Three Dimensional ◽  
Nonlinear Behavior ◽  
Small Deformation ◽  
Contact Problems ◽  
Tangential Direction ◽  
Normal Direction ◽  
Contact Forces ◽  
Contact Boundary ◽  
Normal Contact

In the present study, an incremental variational inequality is described for frictional contact problems with material non linear behavior assumed to be elasto-plastic for the contacting bodies. On the contacting boundaries, the constraint conditions include noninterpenetration along the normal direction of the contact boundary and Coulomb friction law in the sliding direction. After numerical discretization using the finite element method, an effective linear complementary formulation is then established with two unknown variables and two complementary variables for each contact nodal pair. The proposed developments permit a reduced number of unknown variables which are chosen as the gap function for the normal direction and the norm of the incremental sliding displacements for the tangential direction; and the complementary variables are taken as the normal contact forces and slack variables in the tangential directions. The resulting linear complementary equations are then solved employing an explicit Conjugate Gradient Based Projection (CGBP) method in conjunction with a generalized Newton-Raphson iteration procedure to account for the material nonlinear behavior. The methodology is valid for three-dimensional frictional contact representations; however, for purposes of illustration of the proposed approaches, attention is confined to applications involving two-dimensional static elasto-plastic problems under small deformation. Numerical examples are presented which clearly show that the developments satisfy the problem physics and contact conditions with features to include high accuracy and reduced computational costs.

scholarly journals Perbandingan Antara SQLite, Room, dan RBDLiTe Dalam Pembuatan Basis Data pada Aplikasi Android

2020 ◽  
Vol 7 (3) ◽  
pp. 376
Author(s):  
Raden Bagus Dimas Putra ◽  
Eko Setia Budi ◽  
Abdul Rahman Kadafi
Keyword(s):  
Operating System ◽  
Data Structure ◽  
Relational Database ◽  
Program Code ◽  
Entire Data ◽  
Android Applications ◽  
The Common ◽  
Internal Database ◽  
Market Needs

Android is one of the largest mobile operating system platforms today. Amid the ever-increasing needs of users, Android programmers are still lacking to meet the current market needs. One of the problems that causes this is the difficulty of creating an internal database, so many people give up to learn to make Android applications. Android's internal database is hard to create because the entire data structure on that database should be built with the query executed in the created program code. Some of the common internal databases currently used are SQLiTe and Room. Both databases are quite difficult to learn where SQLite should build everything from scratch while Room should study the structure and systematics of of the library. Therefore, in this article, the author proposes library and template named "Relational Database Library and Template" which will be referred to as RBDLiTe which can create an internal database for Android applications easily which will also be compared with SQLiTe and Room in its use.

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