Recent Advances in Mechanical Properties Evaluation of Solid Propellants

Abstract Methods of mechanical properties measurement have become more sophisticated as the necessities of nonlinear stress analysis have been appreciated. The linear cases, typical of low temperature failure, have been successfully handled by elastic analysis, but the nonlinear complexities of the higher temperature regimes require analytical correlation of real properties and analytical methods of using such correlations. The wide variability of mechanical properties observed in solid propellants requires that predictions of failure be based on estimates of upper and lower expected limits rather than viewing failure as a point value, as is often done in stress analysis of metallic structures.

Download Full-text

850.0 and 852.0 ALUMINUM ALLOY BEARING BARS

Alloy Digest ◽

10.31399/asm.ad.al0290 ◽

1988 ◽

Vol 37 (9) ◽

Keyword(s):

Mechanical Properties ◽

Thermal Conductivity ◽

Corrosion Resistance ◽

Aluminum Alloy ◽

Heat Treating ◽

Light Metal ◽

General Purpose ◽

High Ductility ◽

Higher Temperature ◽

Bearing Alloy

Abstract 850.0 ALUMINUM Alloy can be considered the general purpose light metal bearing alloy. Its good thermal conductivity keeps operating temperatures low. It has high ductility. In many applications it has been found to be superior to steel backed bearings. 852.0 ALUMINUM Alloy has higher mechanical properties making it suitable for heavier load and higher temperature applications. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength. It also includes information on corrosion resistance as well as heat treating and machining. Filing Code: Al-290. Producer or source: Federated Bronze Products Inc..

Download Full-text

Regional mechanical properties and stress analysis of the human anterior lens capsule

Vision Research ◽

10.1016/j.visres.2007.03.014 ◽

2007 ◽

Vol 47 (13) ◽

pp. 1781-1789 ◽

Cited By ~ 37

Author(s):

R.M. Pedrigi ◽

G. David ◽

J. Dziezyc ◽

J.D. Humphrey

Keyword(s):

Mechanical Properties ◽

Stress Analysis ◽

Lens Capsule ◽

Anterior Lens Capsule

Download Full-text

Effects of Sr Addition on Mechanical Properties and Microstructure of Mg-6Al Magnesium Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.686.120 ◽

2011 ◽

Vol 686 ◽

pp. 120-124

Author(s):

Jin Ping Fan ◽

She Bin Wang ◽

Bing She Xu

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Magnesium Alloy ◽

Strengthening Mechanism ◽

Microstructure And Mechanical Properties ◽

Higher Temperature ◽

Lower Temperature

The effects of Sr addition on the mechanical properties and microstructure of Mg-6Al mag- nesium alloy both at 25 °C and at 175 °C were investigated by means of OM, SEM and EDS and XRD. Upon the Sr addition of 2%, the tensile strength was increased by 7.2% to 184.4MPa at 25 °C, while it was increased by 30% to 155.4MPa at 175 °C. The strengthening mechanism of Mg-6Al-xSr at lower temperature (25 °C) was different from that at higher temperature (175°C). The results show that the addition of strontium effectively improved the microstructure and mechanical properties of magnesium alloy.

Download Full-text

Effect of Block Molecular Weight on the Mechanical Properties of PA1010-b-PEG Segmented Block Copolymers

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.512-515.2127 ◽

2012 ◽

Vol 512-515 ◽

pp. 2127-2130

Author(s):

Li Huo ◽

Cai Xia Dong

Keyword(s):

Mechanical Properties ◽

Molecular Weight ◽

Block Copolymers ◽

Microphase Separation ◽

Soft Segment ◽

Mechanical Measurements ◽

Wide Range ◽

Hard Block ◽

Higher Temperature ◽

Hard Segments

The mechanical properties were investigated of a series of PA-PEG thermalplastic elastomer based on PA1010 and polytetramethylene glycol (PEG) with varying hard and soft segment content. Dynamic mechanical measurements of these polymers have carried out over a wide range of temperatures. The block copolymers exhibit three peaks, designated as α, β and γ in the tanδ-temperature curve. The α transition shifts to higher temperature with increasing hard block molecular weight. However, at a constant hard molecular weight, the α transition shifts to higher temperature and the damping increases on increasing the soft segment molecular weight. DMA results show that the block copolymers exhibit a microphase separation structure and both soft and hard segments were found to be crystallizable. The degree of phase separation increases with increasing hard block molecular weight.

Download Full-text

Effect of Cr and W on the Crystallization Process, the Microstructure and Properties of Hypoeutectic Silumin to Pressure Die Casting

Archives of Foundry Engineering ◽

10.1515/afe-2016-0060 ◽

2016 ◽

Vol 16 (3) ◽

pp. 109-114 ◽

Cited By ~ 3

Author(s):

T. Szymczak ◽

G. Gumienny ◽

T. Pacyniak

Keyword(s):

Mechanical Properties ◽

Crystallization Process ◽

Die Casting ◽

Intermetallic Phase ◽

Small Extent ◽

Metallographic Analysis ◽

Higher Temperature ◽

Dta Studies ◽

Pressure Die Casting ◽

Additional Phase

Abstract This article presents the results of studies in the hypoeutectic silumin destined for pressure die casting with the simultaneous addition of chromium and tungsten. The study involved the derivative and thermal analysis of the crystallization process, metallographic analysis and mechanical properties testing. Silumin 226 grade was destined for studies. It is a typical silumin to pressure die casting. AlCr15 and AlW8 preliminary alloys were added to silumin. Its quantity allowed to obtain 0.1, 0.2, 0.3 and 0.4% of Cr and W in the tested alloy. Studies of the crystallization process as well as the microstructure of the silumin poured into DTA sampler allowed to state the presence of additional phase containing 0.2% or more Cr and W. It has not occurred in silumin without the addition of above mentioned elements. It is probably the intermetallic phase containing Cr and W. DTA studies have shown this phase crystallizes at a higher temperature range than α (Al) solid solution. In the microstructure of each pressure die casting containing Cr and W the new phases formed. Mechanical properties tests have shown Cr and W additives in silumin in an appropriate amount may increase its tensile strength Rm (about 11%), the yield strength Rp0.2 (about 21%) and to a small extent elongation A.

Download Full-text

Nonlinear Stress Analysis of Titanium Implants by Finite Element Method

Dental Materials Journal ◽

10.4012/dmj.27.633 ◽

2008 ◽

Vol 27 (4) ◽

pp. 633-639 ◽

Cited By ~ 18

Author(s):

Sakae NAGASAWA ◽

Keigo HAYANO ◽

Tooru NIINO ◽

Kazunori YAMAKURA ◽

Takamitsu YOSHIDA ◽

...

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Stress Analysis ◽

Titanium Implants ◽

Nonlinear Stress ◽

Element Method

Download Full-text

Electrochemical Corrosion Finite Element Analysis and Burst Pressure Prediction of Externally Corroded Underground Gas Transmission Pipelines

Journal of Pressure Vessel Technology ◽

10.1115/1.4038224 ◽

2017 ◽

Vol 140 (1) ◽

Cited By ~ 1

Author(s):

Ibrahim M. Gadala ◽

Magd Abdel Wahab ◽

Akram Alfantazi

Keyword(s):

Finite Element ◽

Stress Analysis ◽

Reaction Kinetics ◽

Moving Boundary ◽

Electrochemical Corrosion ◽

Burst Pressure ◽

Element Analysis ◽

Corrosion Defect ◽

Nonlinear Stress ◽

Pipeline Wall

An integrative numerical simulation approach for pipeline integrity analysis is presented in this work, combining a corrosion model, which is the main focus of this paper, with a complementary structural nonlinear stress analysis, using the finite element method (FEM). Potential distributions in the trapped water existing beneath pipeline coating disbondments are modeled in conjunction with reaction kinetics on the corroding exposed steel surface using a moving boundary mesh. Temperature dependencies (25 °C and 50 °C) of reaction kinetics do not greatly affect final corrosion defect geometries after 3-yr simulation periods. Conversely, cathodic protection (CP) levels and pH dependencies within the near-neutral pH range (6.7–8.5) strongly govern depth profiles caused by corrosion, reaching a maximum of ∼3 mm into the pipeline wall. A 0.25 V amplification of CP potential combined with a 0.5 mm widening in disbondment opening size reduces defect penetration by almost 30%. Resulting corrosion defect geometries are used for stress examinations and burst pressure evaluations. Furthermore, nonlinear elastic–plastic stress analysis is carried out using shell elements in order to predict the burst pressure of corroded pipes. Corrosion is modeled by reducing the stiffness of a damaged element that has the dimensions of the defect. The predicted burst pressures are in good agreement with those obtained using an experimental-based formula.

Download Full-text