Modulus of elasticity, MOE -

The modulus of elasticity (MOE) is related to the strength and can be used as a nondestmctive quaUty control test on high cost special refractory shapes such as sHde gate valves employed in the pouring of steel (qv). The sHde gate type must be selected to ensure chemical compatibiUty and it must be used in a way to reduce thermal shock. The performance of a properly selected and used sHde gate is direcdy related to its strength and therefore predicted by its MOE. 

Sugar maple was reacted with propylene and butylene oxide (Rowell etal., 1982). The modulus of elasticity (MOE) and modulus of rupture (MOR), fibre stress at proportional limit, and maximum crushing strength all exhibited a reduction, compared to unmodified samples. Nilsson and Rowell (1983) reacted ponderosa pine with butylene oxide and exposed the wood in an unsterile soil decay test. At low WPGs, severe surface decay due to soft rot and tunnelling bacteria was observed. Such attack was reduced at 15 % WPG,... 

The modulus of elasticity (MOE) is related to the strength and can be used as a nondestructive quality control test on high cost special refractory shapes. 

Gerhards (57) reviewed the results of 12 separate studies on strength properties of fire-retardant-treated wood conducted at the FPL and other laboratories. He concluded that modulus of rupture (MOR) is consistently lower and modulus of elasticity (MOE) and work to maximum load are generally lower for fire-retardant-treated wood than for untreated wood if fire-retardant treatment is followed by kiln drying. The effect may be less or negligible if the fire-retardant-treated wood is air dried instead of kiln dried. The most significant loss was in work to maximum load, a measure of shock resistance or brashness, which averaged 34 percent reduction. 

Figure 7 shows the relationship between the face layer ratio and the modulus of elasticity (MOE) in bending of the composite boards. It was obvious that the MOE increased with an increasing face layer ratio of the composite board, because the elastic modulus of the strand layer was higher than that of the core layer with recycled wood particle. If a simple combination of different elastic bodies was introduced, the MOE of three-layer board can be predicted easily by a cubic equation of face layer ratio. It was thought that the MOE of the composite board shown in Figure 7 was predictable from the MOE data of recycled wood particleboard and strand-board. 

Board properties determined were modulus of rupture (MOR), modulus of elasticity (MOE), swelling and water absorption after 24-hour water soak. Testing was done according to Japanese Industrial Standard (JIS) 5906 except that 130x 25 mm bending specimens were tested over a 50 mm span. 

Figure 5.13. Modulus of elasticity (MOE) and unextracted air-dry density for with-pith radiatapine (Simperingham, 1997).

ASTM D 790 also describes determination of the modulus of elasticity (MOE), or flexural modulus, which is the ratio of stress to corresponding strain. It is calculated by drawing a tangent to the steepest initial straight-line portion of the load-deflection curve, which is essentially a load at which the specimen deflects by 1 in. 

Figure 1 Thermomechanical analysis (TMA) of the hardening of a PF resin in situ in a wood joint. Increase of modulus of elasticity (MOE) of the joint as a function of temperature at a 10°C/min constant heating rate (O) first derivative (A). 

Figure 4 Increase of modulus of elasticity (MOE), at heating rates in the 5°C/min to 40°C/min range, as a function of time for a beech wood joint bonded with a UF resin. Increase of MOE corresponds to resin hardening. 

In the TMA plot in Fig. 7 it is possible to note the interactive nature of the substrate on the curing of the PF adhesive. For example, the modulus of elasticity (MOE) increase curve shows two sections (and a two peak first derivative curve). This indicates formation of entanglement networks of the resin in wood which is not possible on noninteractive substrates such as glass as in Fig. 6. Of course DMA and TMA give equally good results when used on the same wood substrate [379,380]. The ABES technique is also linearly correlated with TMA and DMA results as has been demonstrated by the linear relationship that has been found for both MUF and tannin formaldehyde adhesives in the results of TMA and ABES [381]. 

The variation of pressure during hot pressing can follow different sequences. Quick densification with pressure maximum to enable a high density of the face layer and hence high modulus of elasticity (MOE). Sometimes a second densification step is used. 

The modulus of rupture (MOR), modulus of elasticity (MOE) in bending, and tensile strength (TS) parallel to the board surface are shown in Table 7.16 for fiberboards made from control and acetylated kenaf fiber. Acetylation results in a small decrease in MOR, but about... 

Modulus of Rupture (MOR), Modulus of Elasticity (MOE), and Tensile Strength (TS) Parallel to the Board Surface of Fiberboards Made from Control or Acetylated Kenaf Fiber and 8% Phenolic Resin... 

Table 3 summarizes the Analysis of Variance (ANOVA) results for the effects of treatment (untreated and treated), veneer layer and adhesive spread amount. The results show that there were highly significant interactions between these three variables in terms of Modulus of Rupture (MOR) and Modulus of Elasticity (MOE) of OPS plywood. However, it was also observed that the effect of adhesive spread amount was only moderately significant on the bond integrity of OPS plywood in terms both dry and wet shear strengths. 

Figure 1. Modulus of elasticity (MOE) variation as a function of temperature obtained by thermomechanical analysis (TMA) of different gluten protein-formaldehyde and gluten protein-glyoxal adhesive formulations. Gluten protein hydrolysate produced chemically (G). GA(form) = gluten reacted with...

The treatment of wood fibres with isocyanate-bearing molecules and their incorporation into polyethylene were also recently studied [44]. In particular, the use of poly-(diphenylmethane diisocyanate) (XV) increased both the modulus of rupture (MOR) and the modulus of elasticity (MOE) of the ensuing composites. The use of stearic anhydride (XVI) as a novel compatibilizer further improved both MOR and MOE and enhanced the water resistance of the composites. 

The mechanical property of this study was also reported. The modulus of elasticity (MOE) and modulus of rupture (MOR) of raw wood, WPC and PWPC were measured and results are given in Table 14.1. The MOE of WPC and PWPC were higher than those of their raw ones. It is worth noting that the MOE was more significantly affected by the NaOH pretreatment. This result is expected because NaOH reacts with cellulose in wood and enhances the adhesion and compatibility between wood fibers and the polymer resulting in improved MOE. The higher MOE of both WPC and PWPC... 

Table 14.2 Modulus of elasticity (MOE) and modulus of rupture (MOR) of untreated and treated wood. (Std. standard deviation, HG Homogeneity group).

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