This and other texts I have read concentrate on the elasticity of the racquet. As a tennis player ( and civil engineer ) my experience strongly suggests that the string tension and modulus of elasticity are just if not more important. Many players use different string type in the longitudinal as opposed to the cross strings while others use different tensions. there seems to be little science involved. My inclination is to attempt to share the impact force of the ball equally between the longitudinal and cross strings by using the one string type and a higher tension in the longitudinal strings.
At this stage the mathematics is beyond me so its trial and error. Best results so far are a tension difference of 5 lbs.
Would appreciate any advice.
Garth Wenck . firstname.lastname@example.org