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Solid viscoelastic cylinder bonded to thin elastic casing, analyzing normal and tangential stresses for stress and displacement frequency responses in forced transverse vibration
Viscoelasticity in shearing and accelerative flows by integral theory, discussing stress distribution and pressure drop
Stable and unstable crack growth in viscoelastic media, solving boundary value problem and continuum mechanics prediction of crack propagation
Viscoelastic plate crack growth analysis within continuum mechanics framework as analog to Griffith problem
Viscoelastic-plastic solid delayed fracture associated with wedge formation of crazed material at crack tip
Viscoelastic fluids stratified flow down inclined plane, examining liquids elasticity role in stability
Crack growth study in viscoelastic solids by linear continuum mechanics, discussing cyclic loads, composite solids mechanical behavior and thermodynamics
Describing induced birefringence in viscoelastic materials based on constitutive assumptions for stress and dielectric properties
Hydrodynamic stability of viscoelastic fluid filaments
Photographic method for measuring viscoelastic strain in solid propellants and other materials
VISCEL computer program user manual for analysis of linear viscoelastic structures
Analysis of bond stress in viscoelastic case bonded solid propellant rocket assembly during thermal shock
Covering plate steady state response to acoustic vibrations in viscoelastic half space, calculating interface displacement frequency spectra under zero shear stress assumption
Crack propagation model in linearly viscoelastic solid strip based on thermodynamics first law
Linearly viscoelastic strip with slowly propagating central crack, calculating stress intensity factor and crack opening size
The VISCEL program is a general purpose computer program developed for equilibrium analysis of linear viscoelastic structures. The program is written in FORTRAN 5 language to operate on the Univac 1108 computer under the EXEC 8 operating system. The program, an extension of the linear equilibrium problem solver ELAS, is an updated and extended version of its earlier form written for the IBM 7094 computer. Finite element matrix displacement approach coupled with the synchronized material property concept, utilizing incremental time steps, was adopted for the solution presented. The step-by-step procedure involves solution of recursive equations in the time domain, which takes into account the memory of material properties. Incremental and accumulative displacements and stresses are obtained at the end of each time step. In order to minimize the extent of computations resulting from accumulative effects of material memory, the program provides an option which enables the employment of constant time steps in the logarithmic scale. Program documentation is presented.
This program, an extension of the linear equilibrium problem solver ELAS, is an updated and extended version of its earlier form (written in FORTRAN 2 for the IBM 7094 computer). A synchronized material property concept utilizing incremental time steps and the finite element matrix displacement approach has been adopted for the current analysis. A special option enables employment of constant time steps in the logarithmic scale, thereby reducing computational efforts resulting from accumulative material memory effects. A wide variety of structures with elastic or viscoelastic material properties can be analyzed by VISCEL. The program is written in FORTRAN 5 language for the Univac 1108 computer operating under the EXEC 8 system. Dynamic storage allocation is automatically effected by the program, and the user may request up to 195K core memory in a 260K Univac 1108/EXEC 8 machine. The physical program VISCEL, consisting of about 7200 instructions, has four distinct links (segments), and the compiled program occupies a maximum of about 11700 words decimal of core storage.
Previously a method was developed for predicting the viscoelastic response of polymers undergoing scission reactions. These results are now extended to include crosslinking reactions. As for scission, at any given time the character of the network chains is determined by the instantaneous crosslink density. For scission all chains were assumed to carry the same stress; for crosslinking, however, the stress is distributed between the 'new' and 'old' chains. Equations for calculating the creep response of a system which experiences a step increase in crosslink density are derived.