Evaluation of the Load-Carrying Capacity in Bending of Large Cross Section “Pitch Pine” Beams in Standing Structures

2013 ◽  
Vol 778 ◽  
pp. 410-417 ◽  
Author(s):  
Manuel C. Touza Váquez ◽  
Azahara Soilán Cañás ◽  
David Lorenzo Fouz
Keyword(s):  
Mechanical Properties ◽  
Pinus Palustris ◽  
Strength Properties ◽  
Modulus Of Rupture ◽  
Load Carrying Capacity ◽  
Visual Grading ◽  
Load Carrying ◽  
Pitch Pine ◽  
Large Sections

This paper deals with the procedure followed in order to define a visual grading protocol to determine the mechanical properties of existing old pitch pine timber beams with large sections. The commercial name pitch pine comprises several species in the group of southern yellow pines, being the Longleaf pine or Georgia pitch pine (Pinus palustris) the most important. Old growth Pinus palustris, was very much appreciated for its rigidity, density, strength properties and natural durability. In Spain, many of the buildings constructed with this timber (named as pino tea) are nowadays under rehabilitation processes which, in some cases, will change the previous use of the building. All these interventions require understanding the mechanical properties of the timber. The structural properties of the aged pitch pine timber are unknown and there is not any European stress grading standard to enable the classification of the existing elements. For this reason, a total of 45 large section pitch pine pieces were visually analyzed and graded according to Spanish standard UNE EN 56.544 [. After this, the beams were tested according to UNE EN 408 [ in order to determine their modulus of rupture and flobal modulus of elasticity. All beams were tested keeping their original positions in the building and a new classification system for old beams is proposed based on a reduced number of chief visual grading parameters and taking into account their position into the beam.

scholarly journals Manufacturing, Characterisation and Mechanical Analysis of Polyacrylonitrile Membranes

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2378
Author(s):  
Mertol Tüfekci ◽  
Sevgi Güneş Durak ◽  
İnci Pir ◽  
Türkan Ormancı Acar ◽  
Güler Türkoğlu Demirkol ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Main Idea ◽  
Mechanical Analysis ◽  
Operating Conditions ◽  
Load Carrying Capacity ◽  
The Finite Element Method ◽  
Load Carrying ◽  
The Impact ◽  
Static Behaviour ◽  
Modelling Process

To investigate the effect of polyvinylpyrrolidone (PVP) addition and consequently porosity, two different sets of membranes are manufactured, since PVP is a widely used poring agent which has an impact on the mechanical properties of the membrane material. The first set (PAN 1) includes polyacrylonitrile (PAN) and the necessary solvent while the second set (PAN 2) is made of PAN and PVP. These membranes are put through several characterisation processes including tensile testing. The obtained data are used to model the static behaviour of the membranes with different geometries but similar loading and boundary conditions that represent their operating conditions. This modelling process is undertaken by using the finite element method. The main idea is to investigate how geometry affects the load-carrying capacity of the membranes. Alongside membrane modelling, their materials are modelled with representative elements with hexagonal and rectangular pore arrays (RE) to understand the impact of porosity on the mechanical properties. Exploring the results, the best geometry is found as the elliptic membrane with the aspect ratio 4 and the better RE as the hexagonal array which can predict the elastic properties with an approximate error of 12%.

scholarly journals Sixteen properties of Eucalyptus Tereticornis wood for structural uses

2020 ◽  
Vol 36 (2) ◽  
Author(s):  
Marta Cristina de Jesus Albuquerque Nogueira ◽  
Victor Almeida de Araujo ◽  
Juliano Souza Vasconcelos ◽  
André Luis Christoforo ◽  
Francisco Antonio Rocco Lahr
Keyword(s):  
Mechanical Properties ◽  
Decision Making ◽  
Shear Stress ◽  
Modulus Of Elasticity ◽  
Strength Properties ◽  
Modulus Of Rupture ◽  
Eucalyptus Tereticornis ◽  
Moisture Contents ◽  
Through Diffusion ◽  
Standard Documents

Forest Red Gum eucalypt provides a versatile wood and is converted into different purposes. However, such wood is somewhat limited in structural ends, which highlights the need to exploit this gap through diffusion of mechanical properties of such timber. Obtained results should assist engineers and architects in decision-making for its best building application. This paper studied two physical and fourteen mechanical properties evaluation of Eucalyptus tereticornis at two different moisture contents, following the prescriptions of Brazilian (ABNT NBR 7190: 1997) and North American (ASTM D-143-14: 2014) standard documents. Thus, 1091 repeats were carried out for all properties. By a moisture reduction from 30% to 12%, the bulk density and eleven strength properties statistically showed changes such as modulus of rupture (static bending, parallel and perpendicular compressions), modulus of elasticity (perpendicular compression and static bending), shear stress, tangential cleavage, and parallel and perpendicular hardnesses. Then, the Eucalyptus tereticornis timber could be better usable if is further applied for structural construction uses.

scholarly journals Effect of moisture content on the load carrying capacity and stiffness of corner wood-based and plastic joints

BioResources ◽  
2019 ◽  
Vol 14 (4) ◽  
pp. 8640-8655
Author(s):  
Eliška Máchová ◽  
Nadežda Langová ◽  
Roman Réh ◽  
Pavol Joščák ◽  
Ľuboš Krišťák ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Relative Humidity ◽  
Moisture Content ◽  
Carrying Capacity ◽  
Calculated Data ◽  
Statistical Processing ◽  
Epoxy Adhesive ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Effect Of Moisture

The effect of moisture content on mechanical properties of corner furniture joints was evaluated for when different joining methods and materials were used. Results included statistical processing of the measured and calculated data and evaluation of the effect of selected factors on mechanical properties of joints caused by using mechanical fasteners and glue. The load-carrying capacity and stiffness of corner joints were investigated in two environments, humid and dry, with standard conditions for temperature and pressure, i.e., dry environment had a temperature of 23 °C ± 2 °C and relative humidity of 45% ± 5%, and the humid environment had a temperature of 23 °C ± 2 °C and relative humidity of 90% ± 5%. The two types of materials used were particleboard (PB) with a thickness of 12 mm and artificial stone (plastic) with a thickness of 12 mm. Both materials were tested individually as well as their combination. Epoxy and polyurethane (PUR) adhesives were used for the glued dowel joints. When the same materials were bonded, maximum load carrying capacity was achieved with PUR adhesive, material combination of plastic-plastic, and moisture content of 90%. The epoxy adhesive was most suitable for bonding materials with different properties.

Experimental Study on Mechanical Properties of Axially Loaded PVC Tubed Short Concrete Columns

2011 ◽  
Vol 99-100 ◽  
pp. 715-718 ◽  
Author(s):  
Jun Dong ◽  
De Ping Chen ◽  
Ju Mei Zhao ◽  
De Shan Shan ◽  
Xin Yue Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carrying Capacity ◽  
Loading Condition ◽  
Concrete Strength ◽  
Concrete Columns ◽  
Load Carrying Capacity ◽  
Composite Columns ◽  
Load Carrying ◽  
Strength And Deformation ◽  
Axially Loaded

Twelve PVC tubed short concrete columns and four columns without PVC tube confined were tested under axial load to investigate mechanical properties of axially loaded PVC tubed short concrete columns . The principal influencing factors such as concrete strength, loading condition and ratio of height to diameter were studied. Test results indicated that strength and deformation performance of core concrete increased as a result of the confinement of PVC tube. The PVC tube confinement effect on concrete will decrease with an increase in strength of concrete. Load- carrying capacity and deformation of short composite columns with different loading condition made some difference. As the ratio of height to diameter increases, load- carrying capacity and plasticity of short composite columns decreased gradually.

Mechanical properties of confirmat screws corner joints made of native wood and wood-based composites

2019 ◽  
Vol 105 ◽  
pp. 76-84
Author(s):  
NADEŽDA LANGOVÁ ◽  
PAVOL JOŠČÁK
Keyword(s):  
Mechanical Properties ◽  
Carrying Capacity ◽  
Limit State ◽  
Calculated Data ◽  
Statistical Processing ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Characteristic Values ◽  
State Method

Mechanical Properties of Confirmat Screws Corner Joints Made of Native Wood and Wood-Based Composites. The aim of this investigation was to design and determine the mechanical properties of confirmat screws corner joints made of native wood and wood-based composites. The objective of the study was to ascertain the stiffness and load carrying capacity of joints that differed in the diameter and length of confirmat type screw, as well as in the kind of materials. The results include statistical processing of measured and calculated data, and evaluation of the influence of selected factors on mechanical properties. The results are applied to the calculation of the characteristic values of the properties and to the determination of the equations for their calculation for other values of the selected factors. The characteristic values are used for the evaluation of the joints according to the limit state method.

Mechanical Property Evaluation of Electroplated High Aspect Ratio Microstructures

1998 ◽  
Vol 518 ◽  
Author(s):  
L. S. Stephens ◽  
K.W. Kelly ◽  
E.I. Meletis ◽  
S. Simhadri
Keyword(s):  
Mechanical Properties ◽  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Mold Insert ◽  
Processing Parameters ◽  
Strength Properties ◽  
Knoop Hardness ◽  
Modulus Of Rupture ◽  
Mechanical Seal ◽  
Property Evaluation

AbstractHigh aspect ratio microstructures (HARMs) with a height of hundreds of micrometers and a width of a few tens of micrometers present high promise in a number of challenging fields. At LSU, a number of applications are being developed in which nickel HARMs are electroplated on metal surfaces (mold insert fabrication for the LIGA process, HARMs on mechanical seal faces, HARMs on heat exchange surfaces, etc.). In some of these applications, the HARMs are subjected to high stresses and the mechanical properties are particularly important. These properties can be used to adjust processing parameters to optimize properties of the HARMS.This paper presents a method for measuring the strength properties of cantilevered nickel HARMs constructed by LIGA. Experimentally measured values are reported for modulus of rupture (1280 MPa), Young's modulus (153 GPa) and Knoop hardness (500 Hk) for HARMs with an overplated base. SEM micrographs clearly indicate that failure of the beams is brittle and most frequently occurs at the interface of the beam and overplated base.

scholarly journals Mechanical Properties of Aluminium Bracket Strengthening

2019 ◽  
Vol 65 (4) ◽  
pp. 203-216 ◽  
Author(s):  
A. Ambroziak
Keyword(s):  
Mechanical Properties ◽  
Laboratory Investigation ◽  
Carrying Capacity ◽  
Base Plate ◽  
Outer Diameter ◽  
Load Carrying Capacity ◽  
Middle Point ◽  
Steel Base ◽  
Load Carrying ◽  
Crosshead Displacement

AbstractThe aim of the research is laboratory investigation of aluminium brackets employed to fasten lightweight curtain walls to building facilities. Tensile loads perpendicular to end plates (vertical) were applied here. The author focused on the solutions intended to increase the load-carrying capacity of aluminium brackets applying the plain washer form A (DIN 125; ISO 7089), plain washer with an outer diameter about 3d (DIN 9021; ISO 7093) and additional cover plates (straps) in the location of bolt anchoring on the base plate. The aluminium brackets were tested on a steel base and concrete substrate. The flexibility of anchoring strongly affects the increase of the end plate middle point displacement and movable crosshead displacement.

scholarly journals VARIABILITY OF SOME MECHANICAL PROPERTIES OF SAN RAMON TALL VARIETY OF COCONUT

CORD ◽  
1994 ◽  
Vol 10 (01) ◽  
pp. 34
Author(s):  
R. N. Palomar
Keyword(s):  
Mechanical Properties ◽  
Natural Variation ◽  
Elastic Limit ◽  
Strength Properties ◽  
Modulus Of Rupture ◽  
Average Moisture Content ◽  
Rupture Stress ◽  
Crushing Strength ◽  
The Core ◽  
Strength In Compression

The natural variation of some strength properties of about 80‑year old brown‑and green‑pigmented San Ramon variety of coconut was investigated. The properties were determined from tests on small clear specimens in the air dry condition with an average moisture content of 16.98%. The mechanical properties studied include modulus of rupture, stress at elastic limit and modulus of elasticity in static bending, maximum crushing strength in compression parallel to grain, stress at elastic limit and in compression perpendicular to grain, and shear parallel to grain.   The brown‑pigmented trees showed significantly higher values in all the mechanical properties than the green‑pigmented palms.   For the brown‑and green‑pigmented trees, the values of strength properties markedly decreased with increasing height levels and significantly increased radially from the core to the periphery of the stem.

Simulating the Mechanical and Structural Properties of UltraSTEELTM Dimpled Sheet

2010 ◽  
Vol 450 ◽  
pp. 107-110 ◽  
Author(s):  
Chang J. Wang ◽  
Tarsem Sihra ◽  
Diane J. Mynors ◽  
Bac Nguyen ◽  
Martin English ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Plastic Strain ◽  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
The Novel ◽  
Structural Components ◽  
Structural Behaviour ◽  
Steel Framing ◽  
Load Carrying ◽  
Mechanical And Structural Properties

The novel surface dimpling UltraSTEELTM process developed by Hadley Industries increases the strength of the final rolled products and enhances other product properties such as the load carrying capacity. The dimpled UltraSTEELTM sheet is used in steel framing, ceilings and other structural components. The mechanical properties and structural behaviour of the dimpled sheet are different from plain sheet due to non-uniformly distributed plastic strain and geometry of the dimples.

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