Material properties effects analysis

In a similar vein, I would encourage those engaged in material selection to formally document their selection process using a Material Properties Effects Analysis (MPEA). MPEA involves a systemized approach to material selection, where materials are carefully evaluated for their effect on the system. However, instead of evaluating the effect of failure, the process is used to evaluate the effect of specific material properties. The intent is to determine the critical material properties of the materials that are used in the system. 

Table 5.3 Material Properties Effects Analysis—cont d... 

Professor Martel s book addresses specifically some of the more technical eispects of the risk assessment process, mainly in the areas of hazard identification, and of the consequence/effect analysis elements, of the overall analysis whilst where appropriate setting these aspects in the wider context. The book brings together a substantial corpus of information, drawn from a number of sources, about the toxic, flammable and explosive properties and effect (ie harm) characteristics of a wide range of chemical substances likely to be found in industry eind in the laboratory, and also addresses a spectrum of dangerous reactions of, or between, such substances which may be encountered. This approach follows the classical methodology and procedures of hazard identification, analysing material properties eind... 

The effect of particle size, and hence dispersion, on the coloring properties of aluminum lake dyes has been studied through quantitative measurement of color in compressed formulations [47], It was found that reduction in the particle size for the input lake material resulted in an increase in color strength, and that particles of submicron size contributed greatly to the observed effects. Analysis of the formulations using the parameters of the 1931 CIE system could only lead to a qualitative estimation of the effects, but use of the 1976 CIEL m v system provided a superior evaluation of the trends. With the latter system, the effects of dispersion on hue, chroma, lightness, and total color differences were quantitatively related to human visual perception. 

Solvent absorption measurement has been shown to be a sensitive and useful test method in the manufacture of epoxy powder coatings. A test method was defined and the effects of time and temperature of immersion described. It was shown that solvent absorption is a measure of raw material properties (EEW of the epoxy resin, and CTBN elastomer type and concentration), the homogeneity of the extrudate, as well as the state of cure. The information obtained from solvent absorption measurements has proven to be extremely important not only in quality control analysis but also in providing an insight into the structure function relationships in epoxy resin chemistry. 

Material Properties. The elementary form of the analysis used requires the following properties of propellant during cure tensile modulus, effective bulk modulus, and propellant volume change. Each of these properties changes with temperature and time elapsed since casting. Because of the unusual nature of the material (sticky, wet, explosive, gravel ), special tests, equipment, and techniques were developed for these measurements. 

Analysis of these effects is difficult and time consuming. Much recent work has utilized two-dimensional, finite-difference computer codes which require as input extensive material properties, e.g., yield and failure criteria, and constitutive laws. These codes solve the equations of motion for boundary conditions corresponding to given impact geometry and velocities. They have been widely and successfully used to predict the response of metals to high rate impact (2), but extension of this technique to polymeric materials has not been totally successful, partly because of the necessity to incorporate rate effects into the material properties. In this work we examined the strain rate and temperature sensitivity of the yield and fracture behavior of a series of rubber-modified acrylic materials. These materials have commercial and military importance for impact protection since as much as a twofold improvement in high rate impact resistance can be achieved with the proper rubber content. The objective of the study was to develop rate-sensitive yield and failure criteria in a form which could be incorporated into the computer codes. Other material properties (such as the influence of a hydrostatic pressure component on yield and failure and the relaxation spectra necessary to define viscoelastic wave propagation) are necssary before the material description is complete, but these areas will be left for later papers. 

Underwater acoustics is routinely used in laboratory-scale test facilities for flaw detection, transducer calibration, material property evaluations, and acoustic visualization. In a typical underwater acoustic study, an object of interest is submerged in a water filled tank and acoustically illuminated (insonified). The acoustic signals scattered by the object are then measured and analyzed. If the tank used is not sufficiently large, these measured acoustic signals will include spurious echo components due to extraneous wall reflections. Since the effect of these contaminating echoes usually cannot be removed from the resulting data set by post analysis, they must be prevented from occurring at their source. One cost... 

Soh JLP, Wang F, Boersen N, etal. Modeling the effects of raw material properties and operating parameters on ribbon and granule properties prepared in roller compaction using multivariate data analysis. Drug Dev Ind Pharm. Submitted. 

The biocidal activities of a series of quatemised PUs were examined a inst Staphylococcus aureus and E.coli. The effect of quatemisation on material properties was examined with tensile testing, water absorption analysis, and contact angle measurements. The antibacterial action of the polymers was investigated. 19 refs. 

Analyses have been carried out assuming a cavitated particle, that is, the particle is replaced by a void (see the section Cavitation of the Rubber Particles ). The analysis is applied to an annulus of epoxy resin. The volume fraction of the void is 20%. The elastic material properties used for the epoxy matrix are shown in Table I. The elastic-plastic material properties used are shown in Figure 4. Nonlinear geometric effects were included to take account of large deformations. Final failure of the cell was defined (23) to be the applied strain required for the maximum linear tensile strain in the resin to attain the value of 20%. 

---