Relation of Mechanical Properties to Solid Rocket Motor Failure

1964 ◽  
Vol 37 (2) ◽  
pp. 524-541 ◽  
Author(s):  
Kenneth W. Bills ◽  
James H. Wiegand
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Motor Behavior ◽  
Experimental Studies ◽  
Strain Analysis ◽  
Uniaxial Tensile ◽  
Solid Rocket Motor ◽  
Failure Properties ◽  
Potential Failure ◽  
Solid Rocket

Abstract Experimental studies of propellant specimen and motor behavior during failure provide insight into the probable mechanisms of failure in a composite propellant system. At low rates and high temperatures, failure results from at least two successive processes: first, a dewetting or breaking of the binder to oxidizer bonds, and second, a tearing in the binder structure initiated at points of stress concentration such as regions of binder-oxidizer dewetting. Stress-strain analysis of a motor shows the potential failure points, and a failure analysis indicates the required mechanical properties to withstand failure. Laboratory testing has given a method of classifying propellant behavior, an estimate of material failure variability, and a method of correlating the uniaxial with biaxial tensile properties and with rate and temperature of test. Uniaxial tensile properties are obtained more conveniently by laboratory measurements, but biaxial properties appear to be related more directly to inner bore grain cracking. Good correlations were demonstrated between motor failures in thermal cycling and the failure properties of the propellant from laboratory tests.

Application of Small Punch Test to Evaluate Tensile Properties of SA213T22 Grade Boiler Steel

2015 ◽  
Vol 830-831 ◽  
pp. 191-194
Author(s):  
M. Venkateswara Rao
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Tensile Properties ◽  
Test Methods ◽  
Uniaxial Tensile ◽  
Test Results ◽  
Small Punch Test ◽  
Small Punch ◽  
Punch Test ◽  
Aging Phenomena

Conventional tensile test methods are used for service exposed high temperature boiler tubes to evaluate the deterioration in mechanical properties such as tensile strength, yield strength and percentage elongation. The mechanical properties are required to be evaluated periodically as the boiler components undergo material degradation due to aging phenomena. The aging phenomena occurs due to continuous exposure of tubes to high temperature & pressure steam prevailing inside the tubes and high temperature exposure to corrosive combustible gases from the external surfaces within the boiler.A recent developed new technique called small punch testing has been used to evaluate the tensile properties of SA 213T22 grade steel predominantly exists in super-heater and re-heater sections of boiler. The small punch tests have been carried out on the miniature disk shaped specimens of diameter of 8.0 mm and 0.5 mm thickness extracted from both the new and service exposed tubes. Conventional uniaxial tensile tests on standard specimens from the same tube material have also been performed for comparison. The service exposed tubes showed considerable loss in mechanical properties in both the conventional and small punch test results. Correlations of tensile properties have been obtained based on the comparative analysis of both small punch and uniaxial tensile test results. Further, the study showed that an appropriate empirical relation could be generated for new and service exposed materials between both the techniques. Conventional test methods require large quantity of material removal for test samples from in-service components whereas small punch test method needs only a miniature sample extraction. This small punch test technique could also be extended to evaluate the thicker section boiler components such as pipelines and headers in the boiler as a part of remaining life assessment study. Also this technique could be a useful tool to any metallic component where large quantity of sample removal may be difficult or may not be feasible.

Structure Assessment Using Instrumented Indentation: Strength, Toughness and Residual Stress

2018 ◽  
Author(s):  
Dongil Kwon ◽  
Jong Hyoung Kim ◽  
Ohmin Kwon ◽  
Woojoo Kim ◽  
Sungki Choi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Residual Stress ◽  
Tensile Properties ◽  
Hole Drilling ◽  
Uniaxial Tensile ◽  
Small Scale ◽  
Specimen Preparation ◽  
Instrumented Indentation ◽  
Uniaxial Tensile Testing

The instrumented indentation technique (IIT) is a novel method for evaluating mechanical properties such as tensile properties, toughness and residual stress by analyzing the indentation load-depth curve measured during indentation. It can be applied directly on small-scale and localized sections in industrial structures and structural components since specimen preparation is very easy and the experimental procedure is nondestructive. We introduce the principles for measuring mechanical properties with IIT: tensile properties by using a representative stress and strain approach, residual stress by analyzing the stress-free and stressed-state indentation curves, and fracture toughness of metals based on a ductile or brittle model according to the fracture behavior of the material. The experimental results from IIT were verified by comparing results from conventional methods such as uniaxial tensile testing for tensile properties, mechanical saw-cutting and hole-drilling methods for residual stress, and CTOD test for fracture toughness.

The Effect of Oxygen, Nitrogen, and Hydrogen on the Mechanical Properties of Cb-752

1974 ◽  
Vol 96 (3) ◽  
pp. 201-206 ◽  
Author(s):  
M. W. Mahoney ◽  
N. E. Paton
Keyword(s):  
Mechanical Properties ◽  
Grain Boundaries ◽  
Tensile Properties ◽  
Uniform Distribution ◽  
Base Alloy ◽  
Uniaxial Tensile ◽  
Hardness Testing ◽  
Strength Parameters ◽  
Brittle Transition ◽  
Effect Of Oxygen

Uniaxial tensile properties of the niobium-base alloy Cb-752 have been determined as a function of oxygen, nitrogen, and hydrogen content over a temperature range of −196 C to 200 deg C. Each of these impurities increased the temperature at which a ductile-brittle transition occurs. Although ductility was severely reduced, strength parameters were relatively unchanged making detection of embrittlement by hardness testing difficult. Impurity levels for embrittlement were sufficiently low and the affinity of Cb-752 for contamination sufficiently great that processing operations require strict control. The mechanism of this impurity embrittlement is not well understood. However, observations of fracture surfaces of brittle failures reveal mixed intergranular cleavage with a uniform distribution of precipitates throughout grain boundaries. These observations are discussed in the light of current theories.

Inhomogeneous and Nonlinear Transverse Tensile Properties and Fiber Alignment of Human Supraspinatus Tendon

2009 ◽  
Author(s):  
Spencer P. Lake ◽  
Kristin S. Miller ◽  
Jennifer A. Kadlowec ◽  
Dawn M. Elliott ◽  
Louis J. Soslowsky
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Complex Loading ◽  
Supraspinatus Tendon ◽  
Rotator Cuff Tears ◽  
Uniaxial Tensile ◽  
Initial Alignment ◽  
Fiber Alignment ◽  
Transverse Tensile ◽  
Local Fiber

Rotator cuff tears may be due in part to the complex loading environment of the supraspinatus tendon (SST). Previous research has reported inhomogeneous uniaxial tensile mechanical properties of human SST [1–2] and location-specific collagen fiber alignment distributions that are qualitatively more disperse than other tendons [3–4]. Our group recently measured fiber alignment under load of samples tested along the tendon long-axis and found that re-alignment occurs in the toe-region and varies by SST location [5]. However, the mechanical properties and effect of fiber alignment under more complex loads remain unknown. Examining the properties of SST when tested transverse to the tendon long-axis will evaluate tissue anisotropy and better elucidate possible mechanisms for tissue inhomogeneity and nonlinearity. Therefore, the objectives of this study are to 1) measure local fiber alignment during transverse tensile loading, 2) measure corresponding mechanical properties, and 3) examine structure-function relationships of SST. We hypothesize that 1) fibers will become less aligned during transverse testing, 2) mechanical properties will be greatest in the anterior and bursal locations, and 3) higher initial alignment will correspond to lower transverse tensile properties.

Forming Limit Diagram of the AMS 5599 Sheet Metal

2013 ◽  
Vol 58 (4) ◽  
pp. 1213-1217
Author(s):  
W. Fracz ◽  
F. Stachowicz ◽  
T. Trzepieciński ◽  
T. Pieją
Keyword(s):  
Mechanical Properties ◽  
Sheet Metal ◽  
Plastic Anisotropy ◽  
Experimental Studies ◽  
Forming Limit Diagram ◽  
Forming Limit ◽  
Uniaxial Tensile ◽  
Strain Hardening Exponent ◽  
Uniaxial Tensile Test ◽  
Anisotropy Ratio

Abstract Formability of sheet metal is dependent on the mechanical properties. Some materials form better than others - moreover, a material that has the best formability for one stamping may behave very poorly in a stamping of another configuration. For these reasons, extensive test programs are often carried out in an attempt to correlate material formability with value of some mechanical properties. The formability of sheet metal has frequently been expressed by the value of strain hardening exponent and plastic anisotropy ratio. The stress-strain and hardening behaviour of a material is very important in determining its resistance to plastic instability. However experimental studies of formability of various materials have revealed basic differences in behaviour, such as the ”brass-type” and the ”steel-type”, exhibiting respectively, zero and positive dependence of forming limit on the strain ratio. In this study mechanical properties and the Forming Limit Diagram of the AMS 5599 sheet metal were determined using uniaxial tensile test and Marciniak’s flat bottomed punch test respectively. Different methods were used for the FLD calculation - results of these calculations were compared with experimental results

Solid Rocket Motor Nozzle Flexible Joint Design and Fabrication

2013 ◽  
Vol 631-632 ◽  
pp. 905-909
Author(s):  
Xiao Guang Zhang ◽  
Yu Liu ◽  
Jun Xue Ren ◽  
Jing Xian Yang
Keyword(s):  
Mechanical Properties ◽  
Test Results ◽  
Solid Rocket Motor ◽  
Flexible Joint ◽  
Joint Configuration ◽  
Transfer Molding ◽  
Performance Requirements ◽  
Solid Rocket ◽  
Test Individual ◽  
Ring Material

Design and fabrication of a tactical motor nozzle flexible joint were accomplished in this paper. The miniature flexible joint configuration characteristics were analyzed. The silicone rubber was selected as the elastomer ring material based on the mechanical properties test. Individual reinforcement and elastomer rings were assembled to form the flexible joint by transfer molding. Test results indicate that the flexible joint meet the performance requirements.

Correlation between Alternating Temperature Accelerated Aging and Real World Storage of Composite Propellant

2012 ◽  
Vol 525-526 ◽  
pp. 421-424
Author(s):  
Biao Ding ◽  
Pei Shi ◽  
Xin Qiu
Keyword(s):  
Mechanical Properties ◽  
Real World ◽  
Accelerated Aging ◽  
Solid Rocket Motor ◽  
Composite Propellant ◽  
Accelerated Aging Test ◽  
Aging Test ◽  
Htpb Propellant ◽  
Alternating Temperature ◽  
Solid Rocket

Alternating temperature accelerated aging test was designed to ensure that accelerated aging could preferably simulate real world storage of HTPB composite propellant. Mechanical properties of HTPB propellant aged for three different periods were measured and analyzed. The results indicate that, the tensile strength increased and the elongation decreased after accelerated aging, showing the same trend of real world storage; the mechanical properties of HTPB propellant is strongly influenced by the rate of temperature change; alternating temperature accelerated aging test is consistent well with real world storage. The results can be very helpful for solid rocket motor life prediction.

Application of Instrumented Indentation Technique for Small Scale Testing

2007 ◽  
Author(s):  
Kug-Hwan Kim ◽  
Kyung-Woo Lee ◽  
Ju-Young Kim ◽  
Dongil Kwon ◽  
Kwang-Ho Kim
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Residual Stress ◽  
Tensile Properties ◽  
Pressure Vessel ◽  
Uniaxial Tensile ◽  
Small Scale ◽  
Uniaxial Tensile Test ◽  
Instrumented Indentation ◽  
Indentation Technique

Instrumented indentation technique (IIT) is a novel tool to estimate mechanical properties such as tensile properties, residual stress and fracture toughness by analyzing indentation load-depth curve measured during loading-unloading of indentation. It can be applied directly in small-scale and localized sections of pressure vessel and pipeline since the preparation of specimen is very easy and the experimental procedure is feasible and nondestructive. We present the principles developed for measuring mechanical properties using IIT; the tensile properties by defining the representative stress and strain underneath a spherical indenter, the residual stress near the weldments using the stress-insensitive contact hardness model, and the fracture toughness of ductile metal based on critical indentation energy model. The experimental results from IIT were verified by comparing the results from the conventional methods such as uniaxial tensile test for tensile properties, mechanical saw-cutting and hole-drilling methods for residual stress, and CTOD test for fracture toughness. In particular, the applications of IIT in small scale materials and localized sections of the pressure vessel and pipeline in-use and in-fields are presented.

Strength and Toughness of Graphite Materials for Solid Rocket Motor

2004 ◽  
Vol 449-452 ◽  
pp. 709-712
Author(s):  
Shoichi Nambu ◽  
Manabu Enoki
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Crack Propagation ◽  
Fracture Probability ◽  
Bending Test ◽  
Fracture Toughness Test ◽  
Solid Rocket Motor ◽  
Four Point Bending ◽  
Toughness Test ◽  
Solid Rocket

It was pointed out that one of the causes of recent failure to launch rocket was due to the fracture of nozzle throat insert made of graphite materials. The relationship between mechanical properties and microfracture process in graphite was not enough analyzed. To ensure the reliability of such aerospace equipment, we considered the necessity of assurance by non-destructive evaluation, evaluation of mechanical property for graphite material and design based on fracture probability. In this study, four-point bending test and fracture toughness test were used to evaluate mechanical properties. Mean strength, Weibull parameters, and R-curve for crack propagation were estimated. AE measurement during tests was performed in order to obtain location and stress of microfracture. AE results were analyzed by stochastic process theory. The result of AE demonstrates that microfracture process during bending test is divided into three stages. AE behavior in fracture toughness test was also closely related to crack propagation.

Stress and Strain Analysis of SRM Based on Monitored Shipboard Service Environment

2013 ◽  
Vol 275-277 ◽  
pp. 731-735
Author(s):  
Wei Dong Huang ◽  
Li Ping Zhang
Keyword(s):  
Low Frequency ◽  
Strain Analysis ◽  
Stress And Strain ◽  
Solid Rocket Motor ◽  
Vibration Load ◽  
Service Environment ◽  
Vibration Data ◽  
Low Frequency Vibration ◽  
Effects Of Temperature ◽  
Solid Rocket

Shipboard service environment of solid rocket motor (SRM) was monitored. Based on the monitored temperature and vibration data, the effects of temperature and low frequency vibration load on the stress and strain of SRM were analyzed by ABAQUS. It was shown by the results that the stress and strain of gain fluctuated near the initial thermal stress and strain with the low frequency vibration load. It was also found that the variations in stress and strain of the bonding interface were larger than that of the slot.

Sign in / Sign up

Export Citation Format

Share Document