scholarly journals Issues on the Vibration Analysis of In-Service Laminated Glass Structures: Analytical, Experimental and Numerical Investigations on Delaminated Beams

2019 ◽  
Vol 9 (18) ◽  
pp. 3928 ◽  
Author(s):  
Chiara Bedon
Keyword(s):  
Composite Laminates ◽  
Mechanical Characterization ◽  
Dynamic Performance ◽  
Laminated Glass ◽  
Position Effects ◽  
Vibration Serviceability ◽  
Characterization Of Materials ◽  
Degradation Of Materials ◽  
Static Conditions

Load-bearing laminated glass (LG) elements take the form of simple members in buildings (i.e., columns, beams, and plates) or realize stand-alone assemblies, where glass and other traditional constructional materials can interact. Among several relevant aspects, the dynamic response of LG structures requires dedicated methods of analysis, towards the fulfilment of safe design purposes. A combination of multiple aspects must be taken into account for dynamic calculations of even simple LG elements when compared to static conditions, first of all the sensitivity of common interlayers to the imposed vibration frequency. The challenge is even more complex for the vibration serviceability assessment of in-service LG structures, where the degradation of materials and possible delamination effects could manifest, hence resulting in structural performances that can markedly differ from early-design conditions. Major uncertainties can be associated to the actual mechanical characterization of materials in use (especially the viscoelastic interlayers), as well as the contribution of restraints (as compared to ideal boundaries) and the possible degradation of the bonding layers (i.e., delaminations). All of these aspects are examined in the paper, with the support of extended analytical calculations, on-site experimental measurements, and parametric Finite Element (FE) numerical analyses. When compared to literature efforts accounting for ideal boundaries only, an analytical formulation is proposed to include the effects of flexible restraints in the dynamic performance of general (double) LG beams. Special care is also spent for the presence of possible delaminations, including size and position effects. In the latter case, existing formulations for composite laminates are preliminarily adapted to LG beams. Their reliability and accuracy is assessed with the support of test predictions and parametric FE simulations.

MECHANICAL CHARACTERIZATION OF MATERIALS AND DIAGNOSIS OF STRUCTURES BY INVERSE ANALYSES: SOME INNOVATIVE PROCEDURES AND APPLICATIONS

2014 ◽  
Vol 11 (03) ◽  
pp. 1343002 ◽  
Author(s):  
GIULIO MAIER ◽  
VLADIMIR BULJAK ◽  
TOMASZ GARBOWSKI ◽  
GIUSEPPE COCCHETTI ◽  
GIORGIO NOVATI
Keyword(s):  
Structural Analysis ◽  
Digital Image Correlation ◽  
Residual Stresses ◽  
Mechanical Characterization ◽  
Image Correlation ◽  
Alkali Silica Reaction ◽  
Compression Tests ◽  
Material Models ◽  
Characterization Of Materials

A survey is presented herein of some recent research contributions to the methodology of inverse structural analysis based on statical tests for diagnosis of possibly damaged structures and for mechanical characterization of materials in diverse industrial environments. The following issues are briefly considered: identifications of parameters in material models and of residual stresses on the basis of indentation experiments; mechanical characterization of free-foils and laminates by cruciform and compression tests and digital image correlation measurements; diagnosis, both superficially and in depth, of concrete dams, possibly affected by alkali-silica-reaction or otherwise damaged.

Mechanical characterization of materials for bulk forming using a drop weight testing machine

2010 ◽  
Vol 224 (9) ◽  
pp. 1795-1804 ◽  
Author(s):  
C M A Silva ◽  
P A R Rosa ◽  
P A F Martins
Keyword(s):  
Flow Stress ◽  
Mechanical Characterization ◽  
Low Cost ◽  
Testing Machine ◽  
Operating Conditions ◽  
Proportional Loading ◽  
Bulk Forming ◽  
Drop Weight ◽  
Characterization Of Materials

The main limitation of mechanical testing equipments is nowadays centred in the characterization of materials at medium loading rates. This is particularly important in bulk forming because strain rate can easily reach values within the aforesaid range. The aim of this article is twofold: (a) to present the development of a low-cost, flexible drop weight testing equipment that can easily and effectively replicate the kinematic behaviour of presses and hammers and (b) to provide a new level of understanding about the mechanical characterization of materials for bulk forming at medium rates of loading. Special emphasis is placed on the adequacy of test operating conditions to the functional characteristics of the presses and hammers where bulk forming takes place and to its influence on the flow stress. This is needed because non-proportional loading paths during bulk forming are found to have significant influence on material response in terms of flow stress. The quality of the flow curves that were experimentally determined is evaluated through its implementation in a finite-element computer program and assessment is performed by means of axisymmetric upset compression with friction. Results show that mechanical characterization of materials under test operating conditions that are similar to real bulk forming conditions is capable of meeting the increasing demand of accurate and reliable flow stress data for the benefit of those who apply numerical modelling of process design in daily practice.

Improved Kolsky-bar design for mechanical characterization of materials at high strain rates

2009 ◽  
Vol 20 (11) ◽  
pp. 115701 ◽  
Author(s):  
Bo Song ◽  
Kevin Connelly ◽  
John Korellis ◽  
Wei-Yang Lu ◽  
Bonnie R Antoun
Keyword(s):  
Mechanical Characterization ◽  
High Strain ◽  
Kolsky Bar ◽  
Strain Rates ◽  
High Strain Rates ◽  
Characterization Of Materials

Mechanical characterization of materials at small length scales

2012 ◽  
Vol 26 (2) ◽  
pp. 545-561 ◽  
Author(s):  
Maria F. Pantano ◽  
Horacio D. Espinosa ◽  
Leonardo Pagnotta
Keyword(s):  
Mechanical Characterization ◽  
Small Length ◽  
Length Scales ◽  
Characterization Of Materials

scholarly journals Considerations on the Applicability of Test Methods for Mechanical Characterization of Materials Manufactured by FDM

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 28 ◽  
Author(s):  
Amabel García-Domínguez ◽  
Juan Claver ◽  
Ana María Camacho ◽  
Miguel A. Sebastián
Keyword(s):  
Additive Manufacturing ◽  
Mechanical Characterization ◽  
Test Methods ◽  
Fused Deposition Modelling ◽  
Fused Deposition ◽  
General Test ◽  
Specific Standard ◽  
Characterization Of Materials ◽  
Definition Of

The lack of specific standards for characterization of materials manufactured by Fused Deposition Modelling (FDM) makes the assessment of the applicability of the test methods available and the analysis of their limitations necessary; depending on the definition of the most appropriate specimens on the kind of part we want to produce or the purpose of the data we want to obtain from the tests. In this work, the Spanish standard UNE 116005:2012 and international standard ASTM D638–14:2014 have been used to characterize mechanically FDM samples with solid infill considering two build orientations. Tests performed according to the specific standard for additive manufacturing UNE 116005:2012 present a much better repeatability than the ones according to the general test standard ASTM D638–14, which makes the standard UNE more appropriate for comparison of different materials. Orientation on-edge provides higher strength to the parts obtained by FDM, which is coherent with the arrangement of the filaments in each layer for each orientation. Comparison with non-solid specimens shows that the increase of strength due to the infill is not in the same proportion to the percentage of infill. The values of strain to break for the samples with solid infill presents a much higher deformation before fracture.

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