Abrasion loss
abrasion.RdData from an experiment to investigate how the resistance of ruhher to abrasion is affected by the hardness of the ruhher and its tensile strength.
Format
A data frame with 30 rows and 3 columns:
- abrasion_loss
Loss of rubber over a fixed period of time (in grams per hour)
- hardness
Hardness of the rubber in degrees Shore (the larger the number, the harder the rubber)
- tensile_strength
Tensile strength of the rubber (in kg per squared centimetres)
Source
Davies, O.L. and Goldsmith, P.L. (eds.) (1972) Statistical Methods in Research and Production, 4th Edition, Edinburgh: Oliverand Boyd, 239.
Details
Each of 30 samples of rubber was tested for hardness (in degrees Shore; the larger the number, the harder the rubber) and for tensile strength (measured in kg per square centimetre), and was then subjected to steady abrasion for a fixed time. The weight loss due to abrasion was measured in grams per hour. The data could be analysed by regression with two explanatory variables.
Examples
data(abrasion)
mod <- lm(abrasion_loss ~ tensile_strength + hardness, data = abrasion)
summary(mod)
#>
#> Call:
#> lm(formula = abrasion_loss ~ tensile_strength + hardness, data = abrasion)
#>
#> Residuals:
#> Min 1Q Median 3Q Max
#> -79.385 -14.608 3.816 19.755 65.981
#>
#> Coefficients:
#> Estimate Std. Error t value Pr(>|t|)
#> (Intercept) 885.1611 61.7516 14.334 3.84e-14 ***
#> tensile_strength -1.3743 0.1943 -7.073 1.32e-07 ***
#> hardness -6.5708 0.5832 -11.267 1.03e-11 ***
#> ---
#> Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
#>
#> Residual standard error: 36.49 on 27 degrees of freedom
#> Multiple R-squared: 0.8402, Adjusted R-squared: 0.8284
#> F-statistic: 71 on 2 and 27 DF, p-value: 1.767e-11
#>
plot(abrasion$hardness, abrasion$abrasion_loss, xlab = "Hardness", ylab =
"Abrasion loss")
