Publications and Reports by J. Jäger

The contents of the website:  is a list of new publications in Contact Mechanics and Impact Mechanics by J. Jäger, holder of an engineering diploma from the University of Karlsruhe and a doctor degree from the University of Delft, Netherlands. The doctoral work was promoted by Prof. Kalker in the Netherlands. The present working address is Lauterbach Verfahrenstechnik, Postfach 711 117, D-76338 Eggenstein, Germany.

Private address: J. Jäger, Blattwiesenstr. 7, D-76227 Karlsruhe, Germany, email:

Most publications concern new analytical and numerical results in Contact and Impact Mechanics. Among others, a reduced fricton principle was reported for similar elastic bodies in contact, where the tangential problem is reduced to the normal problem. It was developed as a solution of paradoxical friction effects (Painlevé paradox) and  existence-uniqueness difficulties. Applications are impact problems, fretting, wear, existence and uniqueness problems, self-locking, and machine elements with friction. In the publications below, some examples of this principle are presented, using analytical and numerical methods for the normal solution.

The principle states that the tangential traction between to equal bodies in contact is the difference of the  full slip stress of the contact area and the stick area. Mathematically, it can be written in the following form

q = f (p-p*),  x = f k (z-z*) ,

where the symbol q denotes the tangential traction, p the pressure, x the tangential displacement, z the normal displacement, k a stiffness factor,  and variables with asterisk * characterize values of the stick area. The basic formula  above holds  for unidirectional loading, which can be superposed incrementally for general loading and impact. 

Publication list

Feb. 2002, New analytical and  numerical resurlrs for two-dimensional  contact profiles, Int. J. Solids & Structures, vol. 39, 959-972.

Jan. 2002, Properties of equal bodies in contact with friction,  Proceedings of the seventh Pan American conference of Applied Mechanics, eds: P. Kittl, G. Diaz, D. Mook, J. Geer, Universidad de la Frontera, Temuco, Chile, p. 121-124.

Feb. 2001, Jäger, J., Some comments on recent generalizations of Cattaneo-Mindlin, Int. J. Solids Struct.,  vol. 38, issue 14, 2453-2457.

Jan. 2001, Jäger, J., New analytical and numerical solutions for a flat rounded punch compared with FEM, Contact Mechanics 2001, Seville, Spain, June 18-21, published in: Computational Methods in Contact Mechanics V, Eds.: J. Dominuez, C.A. Brebbia, WIT-press, 2001, pp. 307-316.

Aug. 2000, Jäger, J., A generalized Coulomb law for elastic bodies, Int. Congress ICTAM 2000,  Chicago, Aug. 27 - Sep. 2.

 Oktober 1999, Jäger, J., 3-D loading of Winkler foundations with friction, under revision.

September 1999, Jäger, J., A generalization of Cattaneo-Mindlin for thin strips, J. Appl. Mech., Vol. 66, 1034-1037.

 August 1999, Jäger, J., Equal layers in contact with friction, Int. Conf. Contact Mechanics IV, eds.  L. Gaul, C.A. ,  Brebbia, WIT Press, p. 99-108.

May 1999, Jäger, J., Discussion of: Tangential loading of general 3 D contacts, by M. Ciavarella,J. Appl. Mech., Vol. 66, 1048-1049.

 May 1999, Jäger, J., Uni-axial deformation of a random packing of particles, Arch. Appl. Mech. , Vol. 69, 181-203.

Apr. 1999, Jäger, J., Conditions for the generalization of Cattaneo-Mindlin, GAMM meeting 1999,  ZAMM, Vol. 80, (2000), S383-S384.

Okt. 1998, A new principle in Contact Mechanics, J. Tribology, Vol. 120, p.677-683.

Apr. 1998, Jäger, J., Elastic properties of granular media for different contact surfaces, GAMM-meeting 1998, ZAMM, Z. angew. Math. Mech., 1999, Vol. 79. S415-S416.

Dec. 1997, Jäger, J., Discussion of: Contact between an elliptic contact interface in torsion, by J. F. Cuttino, T. A. Dow, J. Appl. Mech. , Vol. 64, 1022-23.

July 1997, Jäger, J., Linear and nonlinear models for impact with friction, Int. Conference on Contact Mechanics 97, Madrid, Spain, in: Comp. Meth. in Contact Mechanics III, eds: M. H. Aliabadi, A. Samartin, CMP, Southampton, 1997, 41-48.

June 1997, Jäger, J., Half-planes without coupling under contact loading, Arch. Appl. Mech. , Vol. 67, 247-259.

May 1997, Jäger, J., Rigid and elastic models for plane impact with friction, Int. Symp. on Penetration and Impact, ICES 97, San Jose, Costa Rica, May 4-7, 1997, unpublished.

March  1997, Jäger, J., Torsional impact of axisymmetric bodies with friction, presented at the GAMM-meeting in Regensburg, March 24-27, unpublished.

 Sep. 1996, Jäger, J., Stepwise Loading of Half-Spaces in Elliptical Contact, J. Appl. Mech., Vol. 63, 766-773.

Sep. 1996, Jäger, J., Non-Hertzian contact models for ultrasonic impact motors, 2nd European Nonlinear Oscilations Conference, Prague, Sep. 9-13, eds.: L. Pust, F. Pererka, printed by: Publishing House of  Czech Techn. University, Vol. 1, pp. 203-206.

Aug. 1996, Jäger, J., Kalker's method applied to some improper integrals in fracture mechanics, Engng. Fracture Mech., Vol. 54, 229-237.

May 1996, Jäger, J., Ein neues Prinzip der Kontaktmechanik, GAMM meeting, May 27 - 31, Prague, ZAMM, Vol. 77, S143-S144.

Oct. 1995, Jäger, J., Mechanics of ultrasonic motors, Report at  the XII-th International Symposium on Dynamics of Vibroimpact Systems, Russia, Moscow-Zvenigorod, Oct. 22 - 27.

Sep. 1995, Jäger, J., Axi-symmetric bodies of equal material in contact under torsion or shift, Arch. Appl. Mech., Vol. 65, no. 7, pp. 478-487.

July, 1995, Jäger, J., Contact with  friction of elastically similar bodies, Symposium on Recent Developments in Impact Mechanics (in honour of Werner Goldsmith), AMD-Vol. 205, Impact, Waves, and Fracture, ed. by R. C. Batra, A. K. Mal, G. P. MacSithigh, pp. 129-152.

 Oct. 1994, Jäger, J., Oblique Impact of Similar Bodies with Circular Contact, Acta Mech. , Vol. 107, 101-115, 1994.

.June 1994, Jäger, J., Torsional impact of elastic spheres, Archive of Applied Mechanics, Vol. 64, no. 4, 235-248.

Feb. 1994, Jäger, J., Analytical Solutions of Contact-Impact, Key note lecture at Euromech 306, Prague, Sep. 7-9, part of "Mechanics of Contact Impact", edited by Miloslav Okrouhlik, Appl. Mech. Rev., Vol. 47, pp. 35-54.

Sep. 1993, Jäger, J., Elastic contact of equal spheres under oblique forces, Arch. Appl. Mech. , Vol. 63, no. 6, pp. 402-413.

July 13, 1993, Jäger, J., Torsional Loading Histories of Elastic Spheres in Contact, in: Contact Mechanics 93, First Int. Conference', eds.:M. H. Aliabadi, C.  A. Brebbia, Computational Mechanics Publications, Southampton, UK, pp. 405-412.

March 18, 1993, Jäger, J., Oblique Impact of Similar Bodies with Circular Contact, Report: GAMM-Seminar 'Kontakt fester Körper' , Eds.: H. Bufler, P. Wriggers, University Stuttgart.

Oct. 30, 1992, Jäger, J., (Jaeger, Juergen), Elastic Impact with Friction, Doctoral Thesis, TU Delft, formerly: Dep. Maths. & Infs., Delft, The Netherlands.

Oct. 7, 1992, Jäger, J., Elastic contact of spheres under oblique forces, Abstract in: Contact Mechanics International Symposium, Ed.: A. Curnier, Proceedings, October 7 - 9, 1992, Lausanne, Presses  polytechniques et universitaires romandes, Lausanne, Switzerland, pp. 508.

May 29, 1990, Jäger, J., An incremental loading history, Colloquium Euromech 273: Unilateral Contact and Dry Friction, Ed.: J. J. Moreau, La Grande Motte, May 29 - June 1, Université Montpellier II, pp. 77-80.