Dynamic and static mechanical analysis of resin luting cements

Failure of a tree can be caused by a stem breakage, tree uprooting, or branch failure. While the pulling test is used for assessing the first two cases, there is no device-supported method to assess branch failure. A combination of the optical technique, pulling test, and deflection curve analysis could provide a device-supported tool for this kind of assessment. The aim of the work was to perform a structural analysis of branch response to static mechanical loading. The analyses were carried out by finite element simulations in ANSYS using beam tapered elements of elliptical cross-sections. The numerical analyses were verified by the pulling test combined with a sophisticated optical assessment of deflection evaluation. The Probabilistic Design System was used to find the parameters that influence branch mechanical response to loading considering the use of cantilever beam deflection for stability analysis. The difference in the branch’s deflection between the simulation and the experiment is 0.5% to 26%. The high variability may be explained by the variable modulus of the elasticity of branches. The finite element (FE) sensitivity analysis showed a higher significance of geometry parameters (diameter, length, tapering, elliptical cross-section) than material properties (elastic moduli). The anchorage rotation was found to be significant, implying that this parameter may affect the outcome in mechanical analysis of branch behavior. The branch anchorage can influence the deflection of the whole branch, which should be considered in stability assessment.

Download Full-text

The Influence of Sub-Zero Conditions on the Mechanical Properties of Polylactide-Based Composites

Materials ◽

10.3390/ma13245789 ◽

2020 ◽

Vol 13 (24) ◽

pp. 5789

Author(s):

Olga Mysiukiewicz ◽

Mateusz Barczewski ◽

Arkadiusz Kloziński

Keyword(s):

Mechanical Properties ◽

Room Temperature ◽

Mechanical Performance ◽

Mechanical Analysis ◽

Uniaxial Tensile ◽

Uniaxial Tensile Test ◽

Mechanical And Thermal Properties ◽

Scanning Calorimetry ◽

Linseed Cake ◽

Static Mechanical

Polylactide-based composites filled with waste fillers due to their sustainability are a subject of many current papers, in which their structural, mechanical, and thermal properties are evaluated. However, few studies focus on their behavior in low temperatures. In this paper, dynamic and quasi-static mechanical properties of polylactide-based composites filled with 10 wt% of linseed cake (a by-product of mechanical oil extraction from linseed) were evaluated at room temperature and at −40 °C by means of dynamic mechanical analysis (DMA), Charpy’s impact strength test and uniaxial tensile test. It was found that the effect of plasticization provided by the oil contained in the filler at room temperature is significantly reduced in sub-zero conditions due to solidification of the oil around −18 °C, as it was shown by differential scanning calorimetry (DSC) and DMA, but the overall mechanical performance of the polylactide-based composites was sufficient to enable their use in low-temperature applications.

Download Full-text

A study of an embeddable and locatable spinning system via quasi-static mechanical analysis

Textile Research Journal ◽

10.1177/0040517512452946 ◽

2012 ◽

Vol 82 (20) ◽

pp. 2071-2077 ◽

Cited By ~ 6

Author(s):

Hongshan Wang ◽

Zhigang Xia ◽

Weilin Xu

Keyword(s):

Theoretical Analysis ◽

Mechanical Analysis ◽

Static Model ◽

Linear Mass ◽

Tension Distribution ◽

Composite Yarn ◽

Formation Zone ◽

Static Mechanical

In this study, a quasi-static model is built to theoretically analyze the distribution of twists and spinning tension in embeddable and locatable spun (ELS) yarn formation zone. Important equations are also derived to determine inner mechanics and external configurations of the ELS yarn formation zones 1, 2 and 3. Analysis results demonstrate that in zones 1 and 2 the tension distribution on the filament and staple strand is directly proportional to their linear mass and square of delivery speed; the larger weight causes a smaller angle between the responding component and the composite strand axis line. The angle between the composite strands 1 and 2 can be simply calculated by dividing the composite yarn velocity by composite strand velocity. Online photographs are provided to validate theoretical analysis of the ELS yarn formation zone configuration and twist distribution in zones 1 and 2.

Download Full-text

Superiority of Cellulose Non-Solvent Chemical Modification over Solvent-Involving Treatment: Application in Polymer Composite (part II)

Materials ◽

10.3390/ma13132901 ◽

2020 ◽

Vol 13 (13) ◽

pp. 2901 ◽

Cited By ~ 1

Author(s):

Stefan Cichosz ◽

Anna Masek

Keyword(s):

Free Energy ◽

Surface Free Energy ◽

Natural Fibers ◽

Degradation Process ◽

Mechanical Analysis ◽

Planetary Mill ◽

Scanning Calorimetry ◽

Static Mechanical ◽

Ft Ir ◽

Composite Samples

The following article debates on the properties of cellulose-filled ethylene-norbornene copolymer (EN) composites. Natural fibers employed in this study have been modified via two different approaches: solvent-involving (S) and newly developed non-solvent (NS). The second type of the treatment is fully eco-friendly and was carried out in the planetary mill without incorporation of any additional, waste-generating substances. Composite samples have been investigated with the use of spectroscopic methods (FT-IR), differential scanning calorimetry (DSC), static mechanical analysis, and surface-free energy measurements. It has been proved that the possible filler-polymer matrix interaction changes may occur due to the performed modifications. The highest reinforcement was evidenced for the composite sample filled with cellulose treated via a NS approach—TS = (34 ± 2) MPa, Eb = (380 ± 20)%. Additionally, a surface free energy polar part exhibited a significant increase for the same type of modification. Consequently, this could indicate easier wetting of the material which may contribute to the degradation process enhancement. Successfully developed cellulose-filled ethylene-norbornene copolymer composite compromises the rules of green chemistry and sustainable development by taking an advantage of renewable natural resources. This bio-inspired material may become an eco-friendly alternative for commonly used polymer blends.

Download Full-text

On the Robustness of the Volumetric Shrinkage Method in the Context of Variation Simulation

Volume 2A: Advanced Manufacturing ◽

10.1115/imece2014-38472 ◽

2014 ◽

Author(s):

Samuel Lorin ◽

Christoffer Cromvik ◽

Fredrik Edelvik ◽

Lars Lindkvist ◽

Rikard Söderberg

Keyword(s):

Mechanical Analysis ◽

Volumetric Shrinkage ◽

Welding Distortion ◽

Uniform Temperature ◽

Approximate Methods ◽

Melted Region ◽

Welded Structure ◽

Shrinkage Method ◽

Static Mechanical ◽

Variation Simulation

Welding induces high temperatures that cause residual stresses and strains in the welded structure. With a welding simulation, these stresses and strains may be predicted. A full simulation implies performing a transient thermal and a quasi-static mechanical analysis. These analyses usually involve a large number of time steps that leads to long simulation times. For welding distortions, there are approximate methods that require considerably less time. This is useful when simulating large structures or for analyses that use an iterative approach common in optimization or variation simulation. One of these methods is volumetric shrinkage, which has been shown to give reasonable results. Here it is assumed that the driving force in welding distortion is the contraction of the region that has been melted by the weld. In volumetric shrinkage, the nodes that are inside the melted region are assigned a uniform temperature and the distortion is calculated using elastic volumetric shrinkage. Although this method has been shown to give reasonable predictions, we will show that it is sensitive to small perturbations, which is an essential part in variation simulation. We also propose a modification of the volumetric shrinkage method that addresses this lack of robustness; instead of defining the melted region by applying a uniform temperature to the nodes inside the zone, we formulate an optimization problem that finds a temperature distribution such that the local melted volume is preserved. A case study with application to variation simulation has been used to elicit the proposed method.

Download Full-text

Natural Rubber Biocomposites Filled with Phyto-Ashes Rich in Biogenic Silica Obtained from Wheat Straw and Field Horsetail

Polymers ◽

10.3390/polym13071177 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1177

Author(s):

Marcin Masłowski ◽

Justyna Miedzianowska ◽

Maciej Delekta ◽

Agnieszka Czylkowska ◽

Krzysztof Strzelec

Keyword(s):

Natural Rubber ◽

Wheat Straw ◽

Biogenic Silica ◽

Plant Biomass ◽

Mechanical Analysis ◽

Structural Hierarchy ◽

High Temperature Heat Treatment ◽

Link Density ◽

Static Mechanical ◽

The Rich

The rich structural hierarchy of plants permits the obtainment of porous structures which can be expected to show improved performances in fields such as pharmaceuticals and cosmetics, catalysis, drug delivery, adsorption, separation or sensors in various chemical reactions. On the other hand, porous materials can be an active additive to polymer composites. The aim of the study was to obtain natural rubber (NR) biocomposites with the addition of phyto-ashes reach in biogenic silica from plant biomass. For the production of bioadditives, a two-stage method of high-temperature heat treatment was used, preceded by acid hydrolysis of plant tissues in the form of horsetail and wheat straw. Hydrolysis was performed with hydrochloric and citric acid. The efficiency of the processes and their influence on the elemental composition, surface morphology, thermal stability and particle size of the fillers were determined. Modified bioadditives were introduced into the elastomer matrix and their processing properties, as well as the vulcanization characteristics, were examined. Static mechanical properties (tensile strength, elongation at break, stress at 100%, 200% and 300% elongation), dynamic-mechanical analysis and the influence of additives on the cross-link density of the composites were determined. Structural analysis was performed using scanning electron microscopy. It was found that the field horsetail and cereal straw are plants rich in many valuable chemical compounds, especially silica. The specific and appropriate treatment of these plants can lead to bioadditives that significantly affect the properties of rubber materials.

Download Full-text

Two Dimensional Static Mechanical Analysis of Laminated Composite Tube Using ABCDE Matrix with No Correction Factor

International Journal of Mechanics ◽

10.46300/9104.2021.15.12 ◽

2021 ◽

Vol 15 ◽

pp. 107-120

Author(s):

Arno Roland Ngatcha Ndengna ◽

Joel Renaud Ngouanom Gnidakouong ◽

Achille Njomoué Pandong ◽

Ekmon Mbangue

Keyword(s):

Correction Factor ◽

Structural Engineering ◽

Laminated Composite ◽

Mechanical Analysis ◽

Two Dimensional ◽

Composite Tube ◽

Design Engineers ◽

Finite Element Package ◽

Static Mechanical ◽

Distribution Of Stresses

Accurate modeling and prediction of materials properties is of utmost importance to design engineers. In this study, newly developed two-dimensional laminate constitutive equations (LCE) were derived directly from an existing shell model without using a classical correction factor. The resulted LCEs were subsequently used for the first time to analyze a laminated composite tube (LCT) subjected to in plane-loading. This led to additional composite-shell stiffness coefficients which are not currently available in some LCEs. The strains and stresses distribution fields were computed via Matlab. The accuracy and robustness of our analytical method were proven by opposing the as-obtained results of thick and thin LCTs with that of existing theories which use a correction factor. An excellent convergence was observed. Whereas a lower convergence was observed in the case of a laminated shell plate. Results also showed that the thickness ratio χ (2χ=h/R ) considerably influences the mechanical behavior of the LCT. In fact when χ<0.1, the distribution of stresses and strains of the tube were the same for the two opposed theories. When χ>0.1, the distribution of stresses and strains were not the same, hence the contribution of our ABCDE matrix. The new mechanical couplings in our LCE could be well illustrated in a finite element package with visualization tools to observe some intricate deformations which are yet to be seen. Thus the outcome of this work will be of particularly interest to promote advanced scientific and structural engineering applications.

Download Full-text

Coupled Thermo-Elastic Analysis on Cross-Section of Umbilical Cables

Volume 5A: Pipelines, Risers, and Subsea Systems ◽

10.1115/omae2019-96195 ◽

2019 ◽

Author(s):

Jun Yan ◽

Haitao Hu ◽

Qi Su ◽

Qingzhen Lu ◽

Zhixun Yang ◽

...

Keyword(s):

Cross Section ◽

Power Transmission ◽

Mechanical Analysis ◽

Coupled Analysis ◽

Elastic Analysis ◽

Cross Sectional ◽

Static Mechanical ◽

The Cross ◽

Cross Sectional Design ◽

Umbilical Cable

Abstract Umbilical cable is composed of electronic cables, optical cables, steel tubes and structural strengthening components, which can be regarded as a key industrial equipment integrating mechanical and electronic functions. Especially, when it is oriented at the power supply with a relatively high rated voltage, the power transmission will produce a large amount of heat with the sectional temperature rising up, which impacts on the material performance and mechanical responses of the cable and even the whole umbilical. Therefore, the thermo-elastic analysis is the critical technology in the cross-sectional design of umbilical cable. Analytical and numerical methods are proposed to conduct the thermo-elastic analysis of the cross-section. Firstly, the steady-state thermal analysis of cross-section of the umbilical cable is implemented, and the thermal field distribution with different cable ampacity is obtained. Then, the thermo-elastic coupled analysis of the cross-section is presented. It is found that the results are quite different from that of static mechanical analysis, which provide a helpful guide for the design of umbilical structures.

Download Full-text

A Discrete Analysis of Metal-V Belt Drive

6th International Power Transmission and Gearing Conference: Advancing Power Transmission Into the 21st Century ◽

10.1115/detc1992-0040 ◽

1992 ◽

Author(s):

A. Karam ◽

D. Play

Keyword(s):

Computer Software ◽

Numerical Approach ◽

Mechanical Analysis ◽

Power Sharing ◽

Speed Ratio ◽

Belt Drive ◽

Sliding Angle ◽

Differential Motion ◽

Load Distributions ◽

Static Mechanical

Abstract The metal-V belt drive includes a large number of parts which interact between them to transmit power from the input to the output pulleys. A compression belt composed of a great number of struts is maintained by a tension flat belt. Power is them shared into the two belts that moves generally in opposite directions. Due to the particular geometry of the elements and to the great number of parts, a numerical approach achieves the global equilibrium of the mechanism from the elementary part equilibrium. Sliding arc on each pulley can be thus defined both for the compression and tension belts. Finally, power sharing can be calculated as differential motion between the belts, is defined. The first part of the paper will present the different steps of the quasi-static mechanical analysis and their numerical implementations. Load distributions, speed profiles and sliding angle values will be discussed. The second part of the paper will deal to a systematic use of the computer software. Speed ratio, transmitted torque, strut geometry and friction coefficients effect will be analysed in relation with the output parameter variations. Finally, the effect pulley deformable flanges will be discussed.

Download Full-text