Tire Design Methodology Based on Safety Factor to Satisfy Tire Life (Simulation Approach to Truck and Bus Tire Design)

2005 ◽  
Vol 33 (4) ◽  
pp. 195-209 ◽  
Author(s):  
K. Kabe ◽  
K. Rachi ◽  
N. Takahashi ◽  
Y. Kaga
Keyword(s):  
Safety Factor ◽  
Strain Field ◽  
Design Methodology ◽  
Experimental Fact ◽  
Fiber Reinforced ◽  
Breaking Strain ◽  
Rubber Part ◽  
Low Modulus ◽  
Margin Of Safety ◽  
Different Strains

Abstract A tire is not only simply made of rubber, but also twisted cord, which we can call FRR (Fiber Reinforced Rubber). The rubber in FRR is made of many materials, including rubber compound, carbon black, silica, and other materials. FRR is a double composite material, which means a particle reinforced material in a microscopic view and also a fiber reinforced one in a macroscopic view. Therefore, it is very difficult to apply fracture mechanics to the evaluation of tire durability on a practical tire design level. This paper gives a proposal for a new design methodology considering the actual tire condition which gives tire profile growth and rubber aging due to heat build-up under operation. These two issues are especially important for truck and bus tire design. Tire profile growth is a very important one because the change of tire profile induces different strains in the rubber at the same location in the tire during its life. We apply the FEM (Finite Element Modeling) based Double Inflation Pressure (DIP) method to simulate the experimental fact of the change of tire profile. In order to use the relationship between the change of the tire profile and change of rubber properties, like breaking strain in the tire as service time passes, the concept of safety factor is introduced. The low modulus rubber parts in the tire dominate the strain field and allow the large deformations of the tire. Safety factors derived from the strain field are called “Margin of Safety.” On the other hand, the durability of FRR, like the belt layer and carcass layer with the cord part, is evaluated by stress because the FRR part reacts to the stress of the internal pressure and load of the tire. But, the Margin of Safety of the rubber part is more important because the cord part has enough safety factor in comparison with the rubber part. Tire life is predicted with the Margin of Safety described above.

scholarly journals Study on the Model Test of the Antibreaking Effect of Fiber Reinforced Concrete Lining in Tunnel

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Guang-yao Cui ◽  
Xue-lai Wang ◽  
Dao-yuan Wang
Keyword(s):  
Reinforced Concrete ◽  
Safety Factor ◽  
Model Test ◽  
Active Fault ◽  
Fiber Reinforced Concrete ◽  
Structural Safety ◽  
Concrete Lining ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Earthquake Intensity

In order to study the antibreaking effect of the fiber reinforced concrete lining in the tunnel, this paper takes the a subway tunnel engineering project in F2-3 section of Jiujiawan fault as the research background and carries out the antibreaking model test of the fiber reinforced concrete lining in the active fault zone of high earthquake intensity. The results show that the antibreaking effect of the principle stress and the longitudinal strain of the fiber reinforced concrete lining are 30%∼40% and 80%∼90%, respectively, and the minimum value of the structural safety factor is increased by 4∼5 times. The antibreaking effect of hybrid fiber reinforced concrete lining is better than that of steel fiber reinforced concrete lining. The safety of steel polypropylene hybrid fiber reinforced concrete tunnel lining is the highest, and its minimum structural safety factor is 1.62. In the aspect of improving the antibreaking effect of the tunnel, the toughening effect of fiber reinforced concrete is stronger than that of reinforcing. The research results are of great significance to improve the antibreaking effect of tunnels in active fault areas with high earthquake intensity.

Design for Fiber-Reinforced Additive Manufacturing

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Hauke Prüß ◽  
Thomas Vietor
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Design Methodology ◽  
Fiber Reinforced ◽  
Reinforcing Fibers ◽  
Rapid Production ◽  
3D Printers ◽  
Composite Production ◽  
Faster Development ◽  
Am Processes

The continuously decreasing life cycle of modern products leads to new challenges for product development. Additive manufacturing (AM) processes are able to support faster development by rapid production of samples and prototypes. However, the material properties of components produced by common (plastic-) 3D-printers are often insufficient for functional prototyping. A well-established way to improve the properties of plastics is the embedding of reinforcing fibers. Thus, this paper shows a method for fiber-reinforced 3D-printing. Through this combination, several restrictions of conventional composite production can be eased and additional freedoms of design are gained. To support the design of such parts, an adapted design methodology for fiber-reinforced 3D-printing is developed.

scholarly journals Probability justification for a minimum margin of safety when calculating ship machine parts and endurance mechanisms

2020 ◽  
pp. 110-115
Author(s):  
В.К. Румб
Keyword(s):  
Safety Factor ◽  
Modern Technology ◽  
Fundamental Difference ◽  
Large Share ◽  
Strength Factor ◽  
Endurance Strength ◽  
Margin Of Strength ◽  
Margin Of Safety ◽  
Machine Parts ◽  
Minimum Margin

Расчеты прочности при проектировании и создании современной техники являются одним из главных критериев качества и конкурентоспособности изделий машиностроения. Неотъемлемой частью расчета прочности на выносливость является оценка минимально допустимого запаса прочности. Существующая оценка этого запаса на основе данных по отказам деталей несет в себе большую долю субъективизма. Предлагается методика определения минимально допустимого коэффициента запаса прочности. Ее принципиальное отличие от существующих заключается в том, что здесь этот коэффициент запаса прочности подсчитывается с учетом рассеяния характеристик прочности детали и действующих в ней напряжений при заданной вероятности отсутствия усталостного разрушения. Это позволяет исключить многие условности при прогнозировании прочностной надежности деталей и создает предпосылки для получения проектных решений, оптимальных по прочности и массе. Strength calculations in the design and creation of modern technology are one of the main criteria for the quality and competitiveness of engineering products. An integral part of the endurance strength calculation is the assessment of the minimum allowable margin of strength. The existing assessment of this stock, based on data on the failure of parts, carries a large share of subjectivism. It is proposed a method of determining the minimum allowable safety factor. Its fundamental difference from the existing one is that here this strength factor is calculated taking into account the scattering of the characteristics of the strength of the part and the stresses in it at a given probability of absence of fatigue destruction. This eliminates many conventions when predicting the strength of the reliability of parts and creates the prerequisites for obtaining design solutions that are optimal in strength and mass.

scholarly journals KUHN-TUCKER CONDITIONS IN SHAKEDOWN PROBLEMS

1996 ◽  
Vol 2 (5) ◽  
pp. 14-28
Author(s):  
Juozas Atkočiūnas
Keyword(s):  
Cyclic Loading ◽  
Mathematical Programming ◽  
Safety Factor ◽  
Strain Field ◽  
Analysis Problem ◽  
Cyclic Plastic ◽  
Perfectly Plastic ◽  
History Of ◽  
Elastic Perfectly Plastic ◽  
The Moment

An elastic perfectly plastic structure at shakedown to given cyclić loading is under consideration. The stress-strain field of dissipative system in general is related to the history of loading. And only in a particular case, i.e. at the moment prior to the failure of an elastic perfectly plastic structure the distribution of the actual residual forces is unique for each prescribed history of loading (the safety factor of shakedown approaches unity). Nevertheless, there exist some domains where the plastic strains are equal to zero. The residual forces in the statically indeterminate parts of the structure may be non-unique: the stress field is only determined by the equilibrium equations. The extremum energy principle of minimum complementary energy allows to derive the actual residual forces out of all statically admissible residual forces at the moment prior to cyclic plastic failure. Then the stress-strain field analysis problem at the moment prior to the cyclic plastic failure is formulated as a problem of non-linear mathematical programming. Formulating the dual pair of non-linear programming problem (statical and kinematic formulation of analysis problem) the differential constraints are neglected or replaced by algebraic conditions. When the safety factor is approching a unity, the degeneracy of the statical formulation of the analysis problem often can occur. In this case a mathematical model is proposed for obtaining an upper bounds for the displacement at shakedown. It is pointed out that the known Kuhn-Tucker conditions of mathematical programming theory (i.e. compatibility equations of residual strains) in concert with restriction, limiting the maximum value of total energy dissipation, make up the adaptation conditions of the structure to given cyclic loading. Kuhn-Tucker conditions used in above—mentioned problem allow to correctly interprete the physical aspect of the degeneracy problem at shakedown. When the safety factor is larger than unity an artificial degeneracy situation for the statical formulation of analysis problem can be created. Then the mathematical models presented can be applied to the analysis of unloading elastoplastic structures. With this aim in view a fictitious equiplastic structure the behaviour of which is holonomic is derived. The displacements of the fictitious structure enclose the displacements of the actual structure subject to cyclic loading.

Constitutive Relations for Fiber-Reinforced Inelastic Laminated Plates

1984 ◽  
Vol 51 (1) ◽  
pp. 107-113 ◽  
Author(s):  
J. Aboudi ◽  
Y. Benveniste
Keyword(s):  
Stress Field ◽  
Effective Stress ◽  
Strain Field ◽  
Constitutive Relations ◽  
Laminated Plates ◽  
Constitutive Behavior ◽  
Laminated Plate ◽  
Fiber Reinforced ◽  
Cylindrical Bending ◽  
Legendre Expansion

Effective stress-strain relations for inelastic unidirectional composites developed previously are used to derive the gross constitutive behavior of inelastic laminates in which every lamina is fiber-reinforced. The laminated plate is subjected to stretching and bending deformation and the strain field is described by the Love-Kirchhoff hypothesis. The distribution of the resulting stresses across the thickness is necessarily nonlinear and a Legendre expansion formalism is used to determine the stress field. Results are given for cross-ply symmetric laminates under pure cylindrical bending.

Straining Effects in Silica-Filled Elastomers Investigated by Atomic Force Microscopy: From Macroscopic Stretching to Nanoscale Strainfield

2003 ◽  
Vol 76 (1) ◽  
pp. 60-81 ◽  
Author(s):  
A. Lapra ◽  
F. Clément ◽  
L. Bokobza ◽  
L. Monnerie
Keyword(s):  
Atomic Force Microscopy ◽  
Strain Field ◽  
Local Concentration ◽  
Macroscopic Strain ◽  
Precise Description ◽  
Force Microscopy ◽  
Filled Elastomers ◽  
Atomic Force ◽  
Different Strains ◽  
Very High

Abstract Understanding the way fillers can reinforce elastomers requires, among other things, requires a precise description of the behavior of filler aggregates when a macroscopic strain is applied. In this study, Atomic Force Microscopy was used to investigate samples of SBR and PDMS filled with silica. The samples were stretched uniaxially at different strain values (up to 145%) and imaged by Atomic Force Microscopy. The distances between aggregates were followed at the different strains, which allowed calculation of the local strains and comparison of the values obtained with the macroscopic strain value. The main results are (i) that the strain field is highly heterogeneous, depending on the local concentration of filler and (ii) that the strain undergone by elastomer chains can be very high locally, in the regions where distances between aggregates are very short.

Bolstering your margin of safety against natural resource scarcity

2018 ◽  
Vol 34 (7) ◽  
pp. 29-31
Keyword(s):  
Natural Resources ◽  
Design Methodology ◽  
Reading Time ◽  
Resource Scarcity ◽  
Content Type ◽  
Natural Resource Scarcity ◽  
Operational Safety ◽  
Margin Of Safety ◽  
Pertinent Information ◽  
Practical Implications

Purpose This paper aims to review the latest management developments across the globe and pinpoint practical implications from cutting-edge research and case studies. Design/methodology/approach This briefing is prepared by an independent writer who adds their own impartial comments and places the articles in context. Findings This research paper concentrates on the commercial risks NRS throws up for large manufacturing businesses, and how NRS can be approached strategically to position them for sustainable operating success. For a business that must use scarce natural resources to make its products, a combination of specific buffering and bridging strategies can be interwoven to plan and implement the most robust, risk-mitigating margin of operational safety. Originality/value The briefing saves busy executives, strategists and researchers hours of reading time by selecting only the very best, most pertinent information and presenting it in a condensed and easy-to-digest format.

Identification of Shear Properties for Woven Fiber Reinforced Polymer Simulation

2016 ◽  
Author(s):  
Dongyang Yang ◽  
Benoit Stalin ◽  
Yong Xia ◽  
Qing Zhou
Keyword(s):  
Strain Field ◽  
Compressive Strain ◽  
Strain Curve ◽  
Image Correlation ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Shear Tests ◽  
Shear Properties ◽  
Polymer Simulation ◽  
Reinforced Polymer

Finite element simulation of composite materials is still challenging as anisotropy of the material brings difficulty in accurately identifying shear properties for modeling. In this study, ±45° tensile tests, Iosipescu shear tests, rail shear tests and Arcan shear tests are conducted to obtain the engineering shear stress-strain curve of woven fiber reinforced polymer. Digital image correlation method is adopted to obtain the strain field of the specimens. It is indicated that Iosipescu shear tests introduce a strain field close to pure shear state while the other three test types introduce relatively large tensile strain or compressive strain. Shear properties obtained from Iosipescu tests are used to calibrate an extensively used composite material model, Matzenmiller-Lubliner-Taylor (MLT) model. The calibrated MLT model is then verified by simulating Arcan tests with different loading angles. The simulations indicate that MLT model gives reliable predictions on Arcan tests with smaller loading angles, while it overestimates the force-displacement responses at larger loading angles.

Constitutive Behaviour of Lateral Ties Confined Polyolefin Fibre Reinforced Concrete under Monotonic Axial Compression

2012 ◽  
Vol 253-255 ◽  
pp. 367-375 ◽  
Author(s):  
S. Palanivel ◽  
M. Sekar
Keyword(s):  
Reinforced Concrete ◽  
Volume Fraction ◽  
Secondary Reinforcement ◽  
Fiber Reinforced Concrete ◽  
Constitutive Behaviour ◽  
Fiber Reinforced ◽  
Behavioral Differences ◽  
Synthetic Fibers ◽  
The Matrix ◽  
Low Modulus

In this investigation, the combined effect of spacing of lateral ties and volume fraction of polyolefin fibres was studied both experimentally and analytically from the point of deformability characteristics of concrete. Low modulus synthetic fibers such as polyolefin based fibers, it is shown that polyolefin fibers with sufficient tensile strength can successfully enhance the mechanical properties of concrete. The mechanism of delaying and arresting the progressive internal cracking from transition zone to the matrix by the fibres can be made use in passive confinement of concrete. Such concrete was termed as polyolefin fiber reinforced concrete (PFRC). In this study the confinement effectiveness of polyolefin fibres of volume fractions 0.3%,0.5%,0.7%,0.9% and 1.2% in addition to lateral ties of spacing 290mm, 145mm and 75mm on concrete prisms of size 150 ×150 ×300 mm were investigated. Such concrete is termed as confined polyolefin fiber reinforced concrete (CPFRC).This paper presents an analytical model(profile) for predicting the constitutive behaviour of CPFRC based on the experimental and analytical results. A total of seventy two prisms of size 150 ×150 ×300 mm were cast and tested under strain control rate of loading. The increase in strength and strain of CPFRC were used in formulating the constitutive relation. The results of the testing demonstrate the behavioral differences between plain and CPFRC and the ability of the synthetic macro fiber to be used as secondary reinforcement in seismic resistance applications.

scholarly journals Prediction of Stress-Strain Field and Safety Factor of a Hybrid Composite Material

2021 ◽  
Vol 1818 (1) ◽  
pp. 012157
Author(s):  
D. Zelmati ◽  
R. Graine ◽  
N. Sehab ◽  
F. Sehab ◽  
O. Ghelloudj ◽  
...  
Keyword(s):  
Composite Material ◽  
Safety Factor ◽  
Hybrid Composite ◽  
Strain Field ◽  
Stress Strain ◽  
Hybrid Composite Material
Sign in / Sign up

Export Citation Format

Share Document