Research on Tensile Stress Relaxation Characteristics of Pinus sylvestris

2011 ◽  
Vol 704-705 ◽  
pp. 480-485
Author(s):  
Xue Qi Li ◽  
Xi Ming Wang ◽  
Jian Fang Yu
Keyword(s):  
Stress Relaxation ◽  
Moisture Content ◽  
Tensile Stress ◽  
Pinus Sylvestris ◽  
Relaxation Rate ◽  
Initial Stress ◽  
Test System ◽  
Tangential Section ◽  
Change Temperature ◽  
Relaxation Characteristics

This research aims to provide theoretical proof for the further study on the factors of stress relaxation under different conditions. In this study, use Pinus sylvestris and dynamic stress-strain test system, though change temperature and moisture to research the stress relaxation of wood. The results showed that the temperature and moisture content on the stress relaxation have a significant impact. With temperature enhancing or moisture content rising, stress dramatically relaxation and residual stress rapidly decreased. In other words, the initial stress decreased gradually and the relaxation rate was rise. It was also found that, under same conditions, compared with the tangential section of the Pinus sylvestris, the radial section has larger initial stress and smaller stress relaxation rate. Besides, the initial stress of late wood is larger than early wood but the stress relaxation rate is smaller. Key words: Pinus sylvestris, tensile stress relaxation

scholarly journals Experimental Study and Simulation of the Stress Relaxation Characteristics of Machine-Harvested Seed Cotton

2021 ◽  
Vol 11 (21) ◽  
pp. 9959
Author(s):  
Jun Wang ◽  
Hongwen Zhang ◽  
Lei Wang ◽  
Ximei Wei ◽  
Meng Wang ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Stress Relaxation ◽  
Moisture Content ◽  
Cross Section ◽  
Testing Machine ◽  
Maxwell Model ◽  
Maximum Error ◽  
Virtual Prototype ◽  
Seed Cotton ◽  
Relaxation Characteristics

Seed cotton compression molding solves the inconvenience of seed cotton transportation and storage after mechanical harvesting. Stress relaxation is closely related to the performance of the compressed seed cotton. In this study, an electronic universal testing machine with a homemade compression device was used to study the stress relaxation characteristics of machine-harvested seed cotton. The stress relaxation model of machine-harvested seed cotton was established, the influence of test factors on the response indexes was analyzed and, finally, stress relaxation characteristics of machine-harvested seed cotton were simulated. Results show that machine-harvested seed cotton stress relaxation characteristics can be described by the five-element Maxwell model. The equilibrium elastic modulus is negatively correlated with moisture content and cross-section dimensions, and the equilibrium elastic modulus is positively correlated with trash content and compression density. The rapid decay time and the residual stress ratio are negatively correlated with moisture content and compression density, but the influence of trash content and cross-section dimensions are limited. The stress relaxation process of machine-harvested seed cotton was simulated using virtual prototype technology, and the maximum error between the experimental and simulated values was obtained as 4.96%. The feasibility of the virtual prototype technique for the viscoelastic simulation of biomaterials was demonstrated.

Tensile and Tensile Stress Relaxation Properties of Wool/Cotton Plied Yarns

1997 ◽  
Vol 67 (5) ◽  
pp. 378-385 ◽  
Author(s):  
Mari Inoue ◽  
Masako Niwa
Keyword(s):  
Stress Relaxation ◽  
Relative Humidity ◽  
Tensile Stress ◽  
Relaxation Rate ◽  
High Water ◽  
Absorption Properties ◽  
Relaxation Properties ◽  
Fabric Hand ◽  
High Water Absorption ◽  
Basic Objective

The basic objective of this work is to understand the effects of humidity and the ratio of wool and cotton fiber on the initial tensile and tensile stress relaxation properties of plied yarns. These low strain properties relate directly to the fabric hand, appearance, and formability of clothing. We have found that wool/cotton plied yarns have high hygroscopicity, high water absorption properties, and a low stress relaxation rate at high relative humidity. Also, we have adapted the power law to provide a relation between wool fiber content and the values of tensile resilience and stress relaxation rate. Their values are then estimated from the values of tensile resilience and stress relaxation rate of the constituent fibers and the blend composition.

ULTRONZE

Alloy Digest ◽  
1981 ◽  
Vol 30 (5) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Stress Relaxation ◽  
Physical Properties ◽  
Copper Alloy ◽  
High Performance ◽  
Copper Alloys ◽  
Heat Treating ◽  
Bend Strength ◽  
Excellent Corrosion Resistance ◽  
Relaxation Characteristics

Abstract ULTRONZE is a copper alloy also known as Olin Alloy 654. It bridges the gap between standard high-performance copper alloys and beryllium-copper alloys, thus enabling the design of parts with properties previously only attainable with more expensive materials. The alloy has superior stress-relaxation characteristics, good bend performance and excellent corrosion resistance. Among its typical uses are electrical connectors, fuse clips and relay springs. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and bend strength. It also includes information on corrosion resistance as well as forming, heat treating, and machining. Filing Code: Cu-417. Producer or source: Olin Brass.

Research on the Stress-relaxation Characteristics of Cancer Cells Based on Atomic Force Microscope

2012 ◽  
Vol 8 (1) ◽  
pp. 47-49
Author(s):  
Jinghe Wang ◽  
Miao Yu ◽  
Zhichao Wu ◽  
Yingchun Liang ◽  
Shen Dong
Keyword(s):  
Stress Relaxation ◽  
Atomic Force Microscope ◽  
Cancer Cells ◽  
Atomic Force ◽  
Relaxation Characteristics

Correlation of fatigue behavior and dynamic mechanical properties of hybrid composites of polypropylene/short glass fibers/hollow glass beads

2021 ◽  
pp. 089270572199319
Author(s):  
Gustavo B Carvalho
Keyword(s):  
Stress Relaxation ◽  
Flexural Strength ◽  
Relaxation Rate ◽  
Hybrid Composites ◽  
Fatigue Behavior ◽  
Glass Fibers ◽  
Glass Beads ◽  
Hollow Glass ◽  
Dynamic Mechanical ◽  
Short Glass

Ternary hybrid composites of Polypropylene (PP)/Short Glass Fibers (GF)/Hollow Glass Beads (HGB) were prepared using untreated and aminosilane-treated HGB, compatibilized with maleated-PP, and with varying total and relative GF/HGB contents. Static/short-term flexural strength properties data revealed, through lower flexural strength values, that the presence of untreated HGB particles induces to fiber-polymer interfacial decoupling at much higher extent than in the presence of aminosilane-treated HGB particles. This phenomenon is also evident when evaluating the data from displacement-controlled three-point bending fatigue tests. Monitored up to 106 cycles, the analyzed hybrid composites presented distinct performance relative to their fatigue stress relaxation rate: the lower the matrix-reinforcements’ interfacial adhesion, more pronounced the stress relaxation rate as a function of the number of fatigue cycles. Dynamic Mechanical Thermal Analysis (DMTA) results could successfully reveal the hybrid composites behavior at the microstructural level when they were submitted to both static flexural test and fatigue, depending on the degree of interfacial interactions between the polymer matrix of PP and the hybrid reinforcements of GF and HGB (with and without aminosilane surface treatment).

Formation of V-grooves on the (Al,Ga)N surface as means of tensile stress relaxation

2012 ◽  
Vol 353 (1) ◽  
pp. 88-94 ◽  
Author(s):  
Kai Cheng ◽  
M. Leys ◽  
S. Degroote ◽  
H. Bender ◽  
P. Favia ◽  
...  
Keyword(s):  
Stress Relaxation ◽  
Tensile Stress
Sign in / Sign up

Export Citation Format

Share Document