Ultimate and Crushing Strength of Plated Structures

1995 ◽  
Vol 39 (03) ◽  
pp. 250-261 ◽  
Author(s):  
Jeom Kee Paik ◽  
P. Terndrup Pedersen
Keyword(s):  
Rate Sensitivity ◽  
Material Model ◽  
Dynamic Loads ◽  
Elastic Model ◽  
Dynamic Effects ◽  
Rigid Plastic ◽  
Compressive Loads ◽  
Collapse Behavior ◽  
Theoretical Results ◽  
Mathematical Process

An efficient theoretical approach is developed which calculates in the same mathematical process the pre-and post-collapse behavior in addition to the deep-collapse response of plated structures under static/ dynamic compressive loads. In the analysis of complex plated structures, each plate element composing the structure is modeled as one plate unit. Two principal models, one elastic model for analysis of the ultimate strength and the other rigid-plastic model for analysis of the crushing load, for the plate unit subjected to static/dynamic loads are derived theoretically. The models are basically formulated as a quasi-static loading condition, but dynamic effects are included by taking into account the influence of strain rate sensitivity in the material model. The procedure is verified by a comparison of experimental and other theoretical results.

Stress analysis of a tube mill

1973 ◽  
Vol 8 (3) ◽  
pp. 200-208 ◽  
Author(s):  
V Ramamurti ◽  
R S Alwar
Keyword(s):  
Particle Size ◽  
Static Analysis ◽  
Experimental Work ◽  
Static Loading ◽  
Thin Shell ◽  
Dynamic Loads ◽  
Tube Mill ◽  
Normal Operation ◽  
Dynamic Effects ◽  
Theoretical Results

The tube mill is essentially a piece of grinding equipment used in the chemical industries to achieve reduction of particle size. In this article a mill of this type has been analysed for static loading by use of the classical thin-shell theories of Donnell, Sanders, Novozhilov, and Flügge and the results have been compared with each other. Experimental work has been carried out to check the theoretical results and also to determine the effect of dynamic loads. It is observed that for the peripheral velocities encountered in the normal operation of a tube mill the dynamic effects are not very pronounced. Hence the design of a tube mill based on static analysis is quite adequate.

Strain Rate Sensitivity of an Aluminium Alloy under Compressive Loads

2012 ◽  
Vol 548 ◽  
pp. 169-173 ◽  
Author(s):  
Nilamber K. Singh ◽  
Maloy K. Singha ◽  
Ezio Cadoni ◽  
Narinder K. Gupta
Keyword(s):  
Strain Rate ◽  
Aluminium Alloy ◽  
Split Hopkinson Pressure Bar ◽  
Testing Machine ◽  
Rate Sensitivity ◽  
Material Model ◽  
Strain Rate Range ◽  
Hopkinson Pressure Bar ◽  
Compressive Loads ◽  
Pressure Bar

An experimental investigation on the dynamic compressive behaviour of the aluminium alloy, AA6063-T6 in the strain rate range from 0.001s-1 to 850s-1 is reported here. Cylindrical specimens of AA6063-T6 are tested under universal testing machine at quasi-static (0.001s-1) condition, whereas, experiments at high strain rates (110s-1,400s-1,550s-1,700s-1 and 850s-1) are conducted on the traditional split Hopkinson pressure bar setup. The strain hardening in the material is found to increase with increasing strain rate. It is observed that the existing Johnson-Cook material model with appropriate material parameters predicts the dynamic compressive flow stress of AA6063-T3 aluminium alloy precisely.

Stresses in Ultrasonically Assisted Turning

2006 ◽  
Vol 5-6 ◽  
pp. 351-358 ◽  
Author(s):  
N. Ahmed ◽  
A.V. Mitrofanov ◽  
Vladimir I. Babitsky ◽  
Vadim V. Silberschmidt
Keyword(s):  
Ultrasonic Vibration ◽  
Vibration Frequency ◽  
Cutting Forces ◽  
Plastic Material ◽  
Process Zone ◽  
Three Dimensional ◽  
Rate Sensitivity ◽  
High Strength ◽  
Material Model ◽  
Shear Stresses

Ultrasonically assisted turning (UAT) is a novel material-processing technology, where high frequency vibration (frequency f ≈ 20kHz, amplitude a ≈15μm) is superimposed on the movement of the cutting tool. Advantages of UAT have been demonstrated for a broad spectrum of applications. Compared to conventional turning (CT), this technique allows significant improvements in processing intractable materials, such as high-strength aerospace alloys, composites and ceramics. Superimposed ultrasonic vibration yields a noticeable decrease in cutting forces, as well as a superior surface finish. A vibro-impact interaction between the tool and workpiece in UAT in the process of continuous chip formation leads to a dynamically changing stress distribution in the process zone as compared to the quasistatic one in CT. The paper presents a three-dimensional, fully thermomechanically coupled computational model of UAT incorporating a non-linear elasto-plastic material model with strain-rate sensitivity and contact interaction with friction at the chip–tool interface. 3D stress distributions in the cutting region are analysed for a representative cycle of ultrasonic vibration. The dependence of various process parameters, such as shear stresses and cutting forces on vibration frequency and amplitude is also studied.

Finite Deflections of a Rigid-Viscoplastic Strain-Hardening Annular Plate Loaded Impulsively

1968 ◽  
Vol 35 (2) ◽  
pp. 349-356 ◽  
Author(s):  
Norman Jones
Keyword(s):  
Strain Rate ◽  
Strain Hardening ◽  
Strain Rate Sensitivity ◽  
Annular Plate ◽  
Dominant Role ◽  
Plate Thickness ◽  
Rate Sensitivity ◽  
Finite Deflections ◽  
Analytical Treatment ◽  
Rigid Plastic

A relatively simple analytical treatment of the behavior of a rigid-plastic annular plate subjected to an initial linear impulsive velocity profile is presented. The influence of finite deflections has been included in addition to strain-hardening and strain-rate sensitivity of the plate material. It is shown, for deflections up to the order of twice the plate thickness, that strain-hardening is unimportant, strain-rate sensitivity has somewhat more effect, while membrane forces play a dominant role in reducing the permanent deflections.

scholarly journals Simulation Study of Adhesive Material for Sandwich Panel under Edgewise Compression Condition

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1391
Author(s):  
Lanxin Jiang ◽  
Bing Yang ◽  
Shoune Xiao ◽  
Guangwu Yang ◽  
Tao Zhu ◽  
...  
Keyword(s):  
Peak Load ◽  
Adhesive Layer ◽  
Material Model ◽  
Simulation Method ◽  
Adhesive Material ◽  
Element Size ◽  
Influence Degree ◽  
Aluminum Alloy Panels ◽  
Theoretical Results ◽  
Compression Condition

In order to study the interfacial adhesive material simulation method of a sandwich structure with aluminum alloy panels and a low-density foam core under edgewise compression condition, two finite element models were defined using material model no. 185 (MAT 185) adhesive element and tiebreak contact, respectively, by LS-DYNA. Under the conditions of different loading rates, and element sizes, the effects of peak load, energy absorption, failure mode of adhesive layer and the influence degree of the changing condition on the calculated results were compared between the two models, and then compared with the experiment results and theoretical results. The higher the loading rate was, or the smaller the element size was, the higher the peak load was. The simulation results obtained using MAT 185 were closer to the experimental results under the edgewise compression condition.

scholarly journals Attenuation of waves in a viscoelastic peridynamic medium

2019 ◽  
Vol 24 (11) ◽  
pp. 3597-3613 ◽  
Author(s):  
S. A. Silling
Keyword(s):  
Attenuation Coefficient ◽  
Material Properties ◽  
Cutoff Frequency ◽  
Material Model ◽  
One Dimensional ◽  
Spatial Nonlocality ◽  
Dissipative Material ◽  
The Time Domain ◽  
The Relationship ◽  
Theoretical Results

The effect of spatial nonlocality on the decay of waves in a dissipative material is investigated. The propagation and decay of waves in a one-dimensional, viscoelastic peridynamic medium is analyzed. Both the elastic and damping terms in the material model are nonlocal. Waves produced by a source with constant amplitude applied at one end of a semi-infinite bar decay exponentially with distance from the source. The model predicts a cutoff frequency that is influenced by the nonlocal parameters. A method for computing the attenuation coefficient explicitly as a function of material properties and source frequency is presented. The theoretical results are compared with direct numerical simulations in the time domain. The relationship between the attenuation coefficient and the group velocity is derived. It is shown that in the limit of long waves (or small peridynamic horizon), Stokes’ law of sound attenuation is recovered.

Analysis of Traction Curve in Linear Region Considering Volume Viscoelasticity

1999 ◽  
Vol 121 (2) ◽  
pp. 252-258 ◽  
Author(s):  
Narihiko Yoshimura ◽  
Noboru Umemoto ◽  
Tsunamitsu Nakahara
Keyword(s):  
High Pressure ◽  
Shear Stress ◽  
High Speed ◽  
Viscoelastic Model ◽  
Primary Data ◽  
Elastic Model ◽  
Linear Region ◽  
Slip Ratio ◽  
Traction Test ◽  
Theoretical Results

Measurements of the gradient in the linear region of traction curve, where the effects of heat generation and nonlinearity of shear viscosity can be neglected were made for two kinds of synthetic oils, DOP and 5P4E, using a traction tester improved to a precision less than 0.01 percent in slip ratio. The measured results were compared with the theoretical results based on a viscoelastic model for shear stress and on an elastic model for compressibility using primary data of the rheological properties which were obtained not by means of traction test; they were markedly less than the theoretical results under low speed for both oils and also under high speed for DOP. A new analysis of the traction was performed considering volume viscoelasticity for compressibility which relates shear viscoelasticity under high pressure. The theoretical results agree fairly with the measured results.

Dynamic Analysis and Design of Compliant Mechanisms Using the Finite Element Method

2012 ◽  
Vol 163 ◽  
pp. 111-115 ◽  
Author(s):  
Wen Jing Wang ◽  
Li Ge Zhang ◽  
Shu Sheng Bi
Keyword(s):  
Finite Element Method ◽  
Dynamic Model ◽  
Natural Frequency ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
The Finite Element Method ◽  
Dynamic Effects ◽  
Experiment System ◽  
Analysis And Design ◽  
Theoretical Results

Compliant mechanisms gain at least some of their mobility from the deflection of flexible members rather than from movable joints only. Dynamic effects are very important to improving the design of compliant mechanisms. An investigation on the dynamics and synthesis of the compliant mechanisms is presented. The dynamic model of compliant mechanisms is developed at first. The natural frequency and sensitivity are then studied based on the dynamic model. Finally, optimal design of compliant mechanism is investigated. The experimental study of natural frequency is performed. The comparison between the experiment results and the theoretical results verifies the validity of the experiment system and theoretical model.

Amorphous and Semicrystalline Solid Polymers: Experimental and Modeling Studies of Their Inelastic Deformation Behaviors

2005 ◽  
Vol 128 (1) ◽  
pp. 64-72 ◽  
Author(s):  
Fazeel Khan ◽  
Erhard Krempl
Keyword(s):  
Inelastic Deformation ◽  
Rate Sensitivity ◽  
Material Model ◽  
Phenomenological Approach ◽  
Control Mode ◽  
Mode Switching ◽  
Stress Tests ◽  
Solid Polymers ◽  
Constitutive Material Model ◽  
Deformation Behaviors

The study of the inelastic deformation behavior of six amorphous and semicrystalline polymers was performed to develop and verify the capabilities of a constitutive material model. The test conditions consisted of piecewise constant strain rates for loading and unloading. Immediate control mode switching capability permitted using load control for creep and recovery tests. Positive, nonlinear rate sensitivity was observed in all cases for monotonic loading and the prior loading rate was found to have a strong influence on creep, relaxation and strain recovery (emulating creep at zero stress) tests. In particular, a fast prior rate engenders a larger change in the output variable: strain in conditions of creep and stress drop in relaxation. Based on the absence of any distinctive deformation traits, the preponderance of data collected in the experimentation program suggests that both categories of polymers can be modeled using the same phenomenological approach. Modeling of the experimental data is introduced with a uniaxial form of the Viscoplasticity Theory Based on Overstress for Polymers (VBOP). Simulations and model predictions are provided for various loading histories. Additional modifications necessary to extend the theory to finite deformation and inelastic compressibility are then presented. An objective formulation is obtained in the Eulerian framework together with the recently proposed logarithmic spin by Xiao [Xiao, H., Bruhns, O., and Meyers, A., 1997, “Hypoelesticity Model Based Upon the Logarithmic Stress Rate,” J. Elast., 47, pp. 51–68].

Sign in / Sign up

Export Citation Format

Share Document