S = sigma bw / Sigma v Dependent on the strength theory: Sigma v = SQRT ( sigma² + ( alpha0 * phi * tau )²) The different stress states can be taken into account with the correction value alpha0: Sigma bw alpha0= ------------ phi * tau Whereby when tau occurs with alternating torque tau w is used; for pulsating torque tau sch is used; and for static load tauf F is used. phi is dependent upon the strength theory (1, 2 or 1.73). Example: A shaft made of St50 is stressed by the bending moment Mb and the torque Mt. How great is the correction value ã0 in accordance with the shear strain energy theory when: a) bending occurs alternating, torsion resting; b) both occur alternating; c) bending occurs resting, torsion occurs alternating? The limit stress can be taken from the WST1 material data base: sigmabF=450N/mm² sigmabW=250N/mm² tauF=180N/mm² tauW=150N/mm². With phi=SQRT3 a) alpha0 = sigmabW/(phi tauF) = 250 / ( SQRT3 * 180 ) = 0.8 b) alpha0 = sigmabW/(phi tauW) = 250 / ( SQRT3 * 150 ) = 0.96 ÷ 1 c) alpha0 = sigmabW/(phi tauF) = 450 / ( SQRT3 * 150 ) = 1.7The correction value ã0 is ascertained by WL1+ when a material is selected from the data base and the strength values are known.

sigmaz alternating: Sigma vb = Sigma b + Sigma z * Sigma bw / Sigma w sigmaz pulsating: Sigma vb = Sigma b + Sigma z * Sigma bw / Sigma sch sigmaz resting: Sigma vb = Sigma b + Sigma z * Sigma bw / Re

====================================================================== Spring length travel mm Spring force N tau N/mm² S ====================================================================== L0= 27.47ñ0.8 F0= 8.47 tau0 = 86 L1= 39.98 s1= 12.51 F1= 45.62ñ5.38 tauk1= 559 1.39 sh= 10.00 Fh= 29.69 taukh= 364 1.09 L2= 49.98 s2= 22.51 F2= 75.31ñ5.83 tauk2= 923 0.84 Lkn= 45.96 skn= 18.49 Fkn= 63.38 taukn= 777 1.00 Ln= 50.41 sn= 22.94 Fn= 76.58 taun = 777 1.00 ---------------------------------------------------------------------- (S = tau zul. / tau y) Sigma perm./ Sigma q2 = 0.68 Sigma hperm./ Sigma bh = 0.67

Since 1992 we have been able to offer a UNIX version of the HPGL Manager and ZARXE, for DEC and SUN work stations. Although Unix version were sought after in 1990-92, this has now dropped off so that no further development in the Unix area is carried on. Much more successful has been the conversion to Windows. The first HEXAGON Windows version was the HPGL Manager, available in June 1993. All programs were converted after this to Windows. Today, 95% of our orders are for Windows versions. In 1997 we brought out new programs, FED8 for calculation of torsion bars, and TR1 for girder calculation. New and future oriented in all of our programs is the feature, as an alternative to printing out on a printer, the possibility for creating HTML files which can be read by Netscape or Internet Explorer.