Analysis of in- and out-of plane vibrations in a rectangular frame based on two- and three-dimensional structural models

2019 ◽  
Vol 440 ◽  
pp. 412-438 ◽  
Author(s):  
C. Mei
Keyword(s):  
Three Dimensional ◽  
Structural Models ◽  
Rectangular Frame ◽  
Out Of Plane

Numerical and experimental investigation for enhancing the energy absorption capacity of the novel three-dimensional printed sandwich structures

2021 ◽  
pp. 146442072199749
Author(s):  
H Geramizadeh ◽  
S Dariushi ◽  
S Jedari Salami
Keyword(s):  
Energy Absorption ◽  
Sandwich Structures ◽  
Three Dimensional ◽  
Absorption Capacity ◽  
The Novel ◽  
Energy Absorption Capacity ◽  
Fused Deposition ◽  
Honeycomb Sandwich ◽  
Out Of Plane ◽  
Vertical Walls

The current study focuses on designing the optimal three-dimensional printed sandwich structures. The main goal is to improve the energy absorption capacity of the out-of-plane honeycomb sandwich beam. The novel Beta VI and Alpha VI were designed in order to achieve this aim. In the Beta VI, the connecting curves (splines) were used instead of the four diagonal walls, while the two vertical walls remained unchanged. The Alpha VI is a step forward on the Beta VI, which was promoted by filleting all angles among the vertical walls, created arcs, and face sheets. The two offered sandwich structures have not hitherto been provided in the literature. All models were designed and simulated by the CATIA and ABAQUS, respectively. The three-dimensional printer fabricated the samples by fused deposition modeling technique. The material properties were determined under tensile, compression, and three-point bending tests. The results are carried out by two methods based on experimental tests and finite element analyses that confirmed each other. The achievements provide novel insights into the determination of the adequate number of unit cells and demonstrate the energy absorption capacity of the Beta VI and Alpha VI are 23.7% and 53.9%, respectively, higher than the out-of-plane honeycomb sandwich structures.

scholarly journals In-Process Measurement of Three-Dimensional Deformations Based on Speckle Photography

2021 ◽  
Vol 11 (11) ◽  
pp. 4981
Author(s):  
Andreas Tausendfreund ◽  
Dirk Stöbener ◽  
Andreas Fischer
Keyword(s):  
Evaluation Method ◽  
Process Analysis ◽  
Plane Deformation ◽  
Three Dimensional ◽  
Machining Process ◽  
Image Correlation ◽  
Speckle Photography ◽  
Process Measurement ◽  
Out Of Plane ◽  
Plane Deformations

In the concept of the process signature, the relationship between a material load and the modification remaining in the workpiece is used to better understand and optimize manufacturing processes. The basic prerequisite for this is to be able to measure the loads occurring during the machining process in the form of mechanical deformations. Speckle photography is suitable for this in-process measurement task and is already used in a variety of ways for in-plane deformation measurements. The shortcoming of this fast and robust measurement technique based on image correlation techniques is that out-of-plane deformations in the direction of the measurement system cannot be detected and increases the measurement error of in-plane deformations. In this paper, we investigate a method that infers local out-of-plane motions of the workpiece surface from the decorrelation of speckle patterns and is thus able to reconstruct three-dimensional deformation fields. The implementation of the evaluation method enables a fast reconstruction of 3D deformation fields, so that the in-process capability remains given. First measurements in a deep rolling process show that dynamic deformations underneath the die can be captured and demonstrate the suitability of the speckle method for manufacturing process analysis.

Mechanism of the Transition From In-Plane Buckling to Helical Buckling for a Stiff Nanowire on an Elastomeric Substrate

2016 ◽  
Vol 83 (4) ◽  
Author(s):  
Youlong Chen ◽  
Yong Zhu ◽  
Xi Chen ◽  
Yilun Liu
Keyword(s):  
High Performance ◽  
Three Dimensional ◽  
Stretchable Electronics ◽  
Buckling Mode ◽  
Design And Optimization ◽  
Out Of Plane ◽  
Plane Direction ◽  
Plane Displacement ◽  
Helical Buckling ◽  
Selection Of

In this work, the compressive buckling of a nanowire partially bonded to an elastomeric substrate is studied via finite-element method (FEM) simulations and experiments. The buckling profile of the nanowire can be divided into three regimes, i.e., the in-plane buckling, the disordered buckling in the out-of-plane direction, and the helical buckling, depending on the constraint density between the nanowire and the substrate. The selection of the buckling mode depends on the ratio d/h, where d is the distance between adjacent constraint points and h is the helical buckling spacing of a perfectly bonded nanowire. For d/h > 0.5, buckling is in-plane with wavelength λ = 2d. For 0.27 < d/h < 0.5, buckling is disordered with irregular out-of-plane displacement. While, for d/h < 0.27, buckling is helical and the buckling spacing gradually approaches to the theoretical value of a perfectly bonded nanowire. Generally, the in-plane buckling induces smaller strain in the nanowire, but consumes the largest space. Whereas the helical mode induces moderate strain in the nanowire, but takes the smallest space. The study may shed useful insights on the design and optimization of high-performance stretchable electronics and three-dimensional complex nanostructures.

Influence of Interference and Clamping on Fretting Fatigue in Single Rivet-Row Lap Joints

2000 ◽  
Vol 123 (4) ◽  
pp. 686-698 ◽  
Author(s):  
K. Iyer ◽  
C. A. Rubin ◽  
G. T. Hahn
Keyword(s):  
Crack Initiation ◽  
Three Dimensional ◽  
Fretting Fatigue ◽  
Cyclic Stress ◽  
Lap Joints ◽  
Element Analysis ◽  
Out Of Plane ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Fretting Damage

Primary fretting fatigue variables such as contact pressure, slip amplitude and bulk cyclic stresses, at and near the contact interface between the rivet shank and panel hole in a single rivet-row, 7075-T6 aluminum alloy lap joint are presented. Three-dimensional finite element analysis is applied to evaluate these and the effects of interference and clamping stresses on the values of the primary variables and other overall measures of fretting damage. Two rivet geometries, non-countersunk and countersunk, are considered. Comparison with previous evaluations of the fretting conditions in similar but two-dimensional connections indicates that out-of-plane movements and attending effects can have a significant impact on the fatigue life of riveted connections. Variations of the cyclic stress range and other proponents of crack initiation are found to peak at distinct locations along the hole-shank interface, making it possible to predict crack initiation locations and design for extended life.

Stiffened Hangers: an Often Overlooked Tool for Conceptual Design of Tied-Arch Footbridges

2021 ◽  
Author(s):  
Juan José Jorquera-Lucerga ◽  
Juan Manuel GARCÍA-GUERRERO
Keyword(s):  
Low Cost ◽  
Three Dimensional ◽  
Structural Response ◽  
Bending Moments ◽  
Structural Element ◽  
Axial Forces ◽  
Limited Effectiveness ◽  
Out Of Plane ◽  
Arch Bridges ◽  
Fixed End

<p>In tied-arch bridges, the way the arch and the deck are connected may become crucial. The deck is usually suspended from hangers made out of steel pinned cables capable of resisting axial forces only. However, a proper structural response, (both in-plane and out-of-plane) may be ensured by fixing and stiffening the hangers in order to resist, additionally, shear forces and bending moments. This paper studies the effect of different pinned and stiffened hanger arrangements on the structural behavior of the tied-arch footbridges, with the intention of providing designers with useful tools at the early steps of design. As a major conclusion, regarding the in-plane behavior, hangers composed of cables (either with vertical, Nielsen-Löhse or network arrangements) are recommended due to its low cost and ease of erection. Alternatively, longitudinally stiffened hangers, fixed at both ends, can be used. Regarding the out-of-plane behavior, and in addition to three-dimensional arrangements of cables, of limited effectiveness, transversally stiffened hangers fixed at both ends are the most efficient arrangement. A configuration almost as efficient can be achieved by locating a hinge at the end corresponding to the most flexible structural element (normally the arch). Its efficiency is further improved if the cross-section tapers from the fixed end to the pinned end.</p>

Validation of the Stress Predictions in Rolling EHL Contacts Having In-Line Roughness Using the Inverse Method

2006 ◽  
Vol 128 (4) ◽  
pp. 745-752 ◽  
Author(s):  
C. J. Hooke ◽  
K. Y. Li
Keyword(s):  
Fluid Flow ◽  
Inverse Method ◽  
Rough Surfaces ◽  
Three Dimensional ◽  
Plane Flow ◽  
Preliminary Results ◽  
Rolling Contacts ◽  
Out Of Plane ◽  
Transverse Roughness

Using modern EHL programs it is relatively simple to determine the pressures and clearances in rough EHL contacts. The pressures may then be used to calculate the subsurface stresses in the two contacting components. However, the results depend on the assumptions made about the fluid’s rheology. While it is possible to measure the clearances using interferometric techniques, measurement of either the pressures or stresses is extremely difficult. However it is these, rather than the clearances, that determine the life of the contact. In previous papers the authors have described how the inverse method may be used to validate the stress predictions for contacts with transverse roughness. This type of contact has fluid flow in only one plane and it remained necessary to check the results for more general rough surfaces where the flow is three-dimensional. Accordingly, the inverse method is extended, in this paper, to a situation where out-of-plane flow is significant. The paper describes the approach and presents some preliminary results for rolling contacts.

The Optimal Stretching Angle of Honeycomb Paper Core Based on the Fourth Strength Principle

2013 ◽  
Vol 288 ◽  
pp. 256-261 ◽  
Author(s):  
Jian Wu ◽  
Yong Long Wang ◽  
Yang Zhang ◽  
Gai Mei Zhang ◽  
Yan Ping Du
Keyword(s):  
Sampling Method ◽  
Stress Condition ◽  
Three Dimensional ◽  
Force Analysis ◽  
Honeycomb Core ◽  
Out Of Plane ◽  
Equivalent Load

The force analysis on the in-plane and out-of-plane of honeycomb core referring to some related articles is presented. during the transportation of wine, the honeycomb paper core is under three-dimensional stress. According to stress condition in the process of wine packaging and transportation, based on the fourth strength principle, the equivalent load is obtained. And the stress with different stretching angels with virtual sampling method is calculated. Thus, the optimal stretching angle of honeycomb paper is acquired, which is .

scholarly journals Epifluorescence-based three-dimensional traction force microscopy

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Lauren Hazlett ◽  
Alexander K. Landauer ◽  
Mohak Patel ◽  
Hadley A. Witt ◽  
Jin Yang ◽  
...  
Keyword(s):  
Spatial Frequency ◽  
Open Source ◽  
Single Particle ◽  
Three Dimensional ◽  
Traction Force ◽  
High Spatial Frequency ◽  
Epifluorescence Microscopy ◽  
Traction Force Microscopy ◽  
Force Microscopy ◽  
Out Of Plane

Abstract We introduce a novel method to compute three-dimensional (3D) displacements and both in-plane and out-of-plane tractions on nominally planar transparent materials using standard epifluorescence microscopy. Despite the importance of out-of-plane components to fully understanding cell behavior, epifluorescence images are generally not used for 3D traction force microscopy (TFM) experiments due to limitations in spatial resolution and measuring out-of-plane motion. To extend an epifluorescence-based technique to 3D, we employ a topology-based single particle tracking algorithm to reconstruct high spatial-frequency 3D motion fields from densely seeded single-particle layer images. Using an open-source finite element (FE) based solver, we then compute the 3D full-field stress and strain and surface traction fields. We demonstrate this technique by measuring tractions generated by both single human neutrophils and multicellular monolayers of Madin–Darby canine kidney cells, highlighting its acuity in reconstructing both individual and collective cellular tractions. In summary, this represents a new, easily accessible method for calculating fully three-dimensional displacement and 3D surface tractions at high spatial frequency from epifluorescence images. We released and support the complete technique as a free and open-source code package.

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