Target Shape Optimization of Functionally Graded Shape Memory Alloy Compliant Mechanism

2016 ◽  
Author(s):  
Jovana Jovanova ◽  
Mary Frecker ◽  
Reginald F. Hamilton ◽  
Todd A. Palmer
Keyword(s):  
Mechanical Properties ◽  
Shape Memory ◽  
Young’S Modulus ◽  
Modulus Of Elasticity ◽  
Compliant Mechanism ◽  
Young's Modulus ◽  
Functionally Graded ◽  
Nsga Ii ◽  
Target Shape ◽  
Young’S Modulus Of Elasticity

Nickel Titanium (NiTi) shape memory alloys (SMAs) exhibit shape memory and/or superelastic properties, enabling them to demonstrate multifunctionality by engineering microstructural and compositional gradients at selected locations. This paper focuses on the design optimization of NiTi compliant mechanisms resulting in single-piece structures with functionally graded properties, based on user-defined target shape matching approach. The compositionally graded zones within the structures will exhibit an on demand superelastic effect (SE) response, exploiting the tailored mechanical behavior of the structure. The functional grading has been approximated by allowing the geometry and the superelastic properties of each zone to vary. The superelastic phenomenon has been taken into consideration using a standard nonlinear SMA material model, focusing only on 2 regions of interest: the linear region of higher Young’s modulus of elasticity and the superelastic region with significantly lower Young’s modulus of elasticity. Due to an outside load, the graded zones reach the critical stress at different stages based on their composition, position and geometry, allowing the structure morphing. This concept has been used to optimize the structures’ geometry and mechanical properties to match a user-defined target shape structure. A multi-objective evolutionary algorithm (NSGA II - Non-dominated Sorting Genetic Algorithm) for constrained optimization of the structure’s mechanical properties and geometry has been developed and implemented.

scholarly journals Rapid methods for the evaluation of total phenol content and extractability in intact grape seeds of Cabernet-Sauvignon: instrumental mechanical properties and FT-NIR spectrum

OENO One ◽  
2012 ◽  
Vol 46 (1) ◽  
pp. 29 ◽  
Author(s):  
Luca Rolle ◽  
Fabrizio Torchio ◽  
Bénédicte Lorrain ◽  
Simone Giacosa ◽  
Susana Río Segade ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Modulus Of Elasticity ◽  
Young's Modulus ◽  
Total Phenol ◽  
Total Phenol Content ◽  
Cabernet Sauvignon ◽  
Phenol Content ◽  
Grape Seeds ◽  
Young’S Modulus Of Elasticity

<p style="text-align: justify;"><strong>Aims</strong>: Fourier Transform-Near Infrared (FT-NIR) spectrum and instrumental texture parameters were assessed as total phenol content and extractability predictors in intact grape seeds.</p><p style="text-align: justify;"><strong>Methods and results</strong>:The study was carried out on Cabernet-Sauvignon seeds from grapes harvested at six different advanced physiological stages throughout ripening and calibrated by flotation to reduce the in-field heterogeneity inside each sample. Among the instrumental mechanical properties tested (i. e., break force, break energy, Young’s modulus of elasticity and deformation index), the seed Young’s modulus of elasticity showed an increase during the first four weeks of ripening. This parameter also showed significant correlations with phenol content and extractability, although with low R coefficients. These correlations highlighted that the springier seed tissues greatly increase phenol extractability. Nevertheless, the best prediction of seed phenol content, performed directly on intact seeds, was found using FT-NIR spectroscopy in transmittance mode. The standard error of prediction for total phenol content was less than 8 %, while that for phenol extractability was worse.</p><p style="text-align: justify;"><strong>Conclusion</strong>: On the basis of these results, the two analytical methods could be applied in oenology for the rapid monitoring of seed phenolic maturity.</p><p style="text-align: justify;"><strong>Significance and impact of the study</strong>: The phenolic composition of grapes at the harvest time is a key factor determining their quality, and thus the quality of the finished wine. The chemical methods used for the determination of seed phenol content and extractability are generally slow because they require a preliminary extraction. Therefore, a rapid evaluation of these parameters could be highly interesting for the oenological sector.</p>

scholarly journals Experimental work for mechanical properties of brick and masonry panel

2018 ◽  
Vol 5 ◽  
pp. 51-57
Author(s):  
Saroj Phaiju ◽  
Prachand Man Pradhan
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Young’S Modulus ◽  
Modulus Of Elasticity ◽  
Young's Modulus ◽  
Strength Properties ◽  
Brick Masonry ◽  
Masonry Walls ◽  
The World ◽  
Young’S Modulus Of Elasticity

The use of Masonry panels in building construction has been popular in most of the parts of the world. However, the use of bricks and brick masonry in different parts of the world being of different nature in terms of quality, size, workmanship of construction, etc. It is yet a topic of interest to researchers to identify the mechanical properties, like Young’s modulus of elasticity and shear modulus of brick masonry panels. It is essential to know the characteristic of brick masonry panels in order to evaluate the responses of masonry walls for any kind of loading. Individual bricks do possess better compressive capacity as compared to masonry walls. Masonry walls are bound together with either mud mortar or by cement sand mortars of various mixes as per the strength requirements. The essential strength properties in engineering are basically the compressive strength and the modulus of elasticity. The American Society for Testing and Materials (ASTM) standard is the most popular for testing bricks and brick masonry for these properties so far. Here, the study has been concentrated in finding the compressive strength of brick, mortar and brick masonry. The study is also done for Young’s modulus of elasticity of brick as well as that of masonry wall. Similarly, the study is extended to find the modulus of rigidity of brick masonry panel. The study is done experimentally for the samples that are generally used in Kathmandu, Nepal. The samples include bricks, cement and sand particularly available in Kathmandu region.

scholarly journals Effect of Nanopores on Mechanical Properties of the Shape Memory Alloy

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 529
Author(s):  
Chunzhi Du ◽  
Zhifan Li ◽  
Bingfei Liu
Keyword(s):  
Mechanical Properties ◽  
Constitutive Model ◽  
Shape Memory ◽  
Young’S Modulus ◽  
Residual Strain ◽  
Surface Effect ◽  
Young's Modulus ◽  
Strain Curve ◽  
Stress Strain ◽  
Strength Limit

Nanoporous Shape Memory Alloys (SMA) are widely used in aerospace, military industry, medical and health and other fields. More and more attention has been paid to its mechanical properties. In particular, when the size of the pores is reduced to the nanometer level, the effect of the surface effect of the nanoporous material on the mechanical properties of the SMA will increase sharply, and the residual strain of the SMA material will change with the nanoporosity. In this work, the expression of Young’s modulus of nanopore SMA considering surface effects is first derived, which is a function of nanoporosity and nanopore size. Based on the obtained Young’s modulus, a constitutive model of nanoporous SMA considering residual strain is established. Then, the stress–strain curve of dense SMA based on the new constitutive model is drawn by numerical method. The results are in good agreement with the simulation results in the published literature. Finally, the stress-strain curves of SMA with different nanoporosities are drawn, and it is concluded that the Young’s modulus and strength limit decrease with the increase of nanoporosity.

Manufacturing and Measuring Mechanical Properties of Continuous Functionally Graded Beam

2021 ◽  
Vol 21 (2) ◽  
pp. 7-11
Author(s):  
Ahmed Mansoor Abbood ◽  
Haider K. Mehbes ◽  
Abdulkareem. F. Hasan
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Volume Fraction ◽  
Young's Modulus ◽  
Functionally Graded ◽  
High Concentration ◽  
Functionally Graded Beam ◽  
Low Concentration ◽  
Graded Material ◽  
Vertical Gravity

In this study, glass-filled epoxy functionally graded material (FGM) was prepared by adopting the hand lay-up method. The vertical gravity casting was used to produce a continuous variation in elastic properties. A 30 % volume fraction of glass ingredients that have mean diameter 90 μm was spread in epoxy resin (ρ = 1050 kg/m3). The mechanical properties of FGM were evaluated according to ASTM D638. Experimental results showed that a gradually relationship between Young’s modulus and volume fraction of glass particles, where the value of Young’s modulus at high concentration of glass particles was greater than that at low concentration, while the value of Poisson’s ratio at high concentration of glass particles was lower than that at low concentration. The manufacture of this FG beam is particularly important and useful in order to benefit from it in the field of various fracture tests under dynamic or cyclic loads.

THE INFLUENCE OF SEX HORMONES ON THE BONY CHANGES OCCURRING IN PARALYSED LIMBS

1954 ◽  
Vol 11 (1) ◽  
pp. 66-70 ◽  
Author(s):  
J. A. GILLESPIE
Keyword(s):  
Young’S Modulus ◽  
Sex Hormones ◽  
Modulus Of Elasticity ◽  
Young's Modulus ◽  
Bending Moment ◽  
Breaking Point ◽  
Total Weight ◽  
Breaking Stress ◽  
Young’S Modulus Of Elasticity ◽  
Ash Weight

SUMMARY 1. Paralysis, produced in young male rats by avulsion of peripheral nerves, resulted in a highly significant reduction in the total weight, ash weight, ash percentage, X-ray density and bending moment at the breaking point, of the bones of the affected limb. The breaking stress was significantly reduced, but Young's modulus of elasticity was unaltered. 2. Certain of these changes were modified by treatment with sex hormones. Both oestradiol and testosterone significantly reduced the difference between the bones of the normal and paralysed limbs in respect of total weight, ash weight and bending moment at the breaking point. 3. Treatment with oestradiol significantly increased both the ash percentage and Young's modulus of elasticity, the increase affecting equally the bones of the normal and paralysed limbs. Testosterone treatment did not significantly affect either of these properties, and neither hormone affected the breaking stress.

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