Valentin L Popov Markus Hess Popular Books
Valentin L Popov Markus Hess Biography & Facts
Contact mechanics is the study of the deformation of solids that touch each other at one or more points. A central distinction in contact mechanics is between stresses acting perpendicular to the contacting bodies' surfaces (known as normal stress) and frictional stresses acting tangentially between the surfaces (shear stress). Normal contact mechanics or frictionless contact mechanics focuses on normal stresses caused by applied normal forces and by the adhesion present on surfaces in close contact, even if they are clean and dry. Frictional contact mechanics emphasizes the effect of friction forces. Contact mechanics is part of mechanical engineering. The physical and mathematical formulation of the subject is built upon the mechanics of materials and continuum mechanics and focuses on computations involving elastic, viscoelastic, and plastic bodies in static or dynamic contact. Contact mechanics provides necessary information for the safe and energy efficient design of technical systems and for the study of tribology, contact stiffness, electrical contact resistance and indentation hardness. Principles of contacts mechanics are implemented towards applications such as locomotive wheel-rail contact, coupling devices, braking systems, tires, bearings, combustion engines, mechanical linkages, gasket seals, metalworking, metal forming, ultrasonic welding, electrical contacts, and many others. Current challenges faced in the field may include stress analysis of contact and coupling members and the influence of lubrication and material design on friction and wear. Applications of contact mechanics further extend into the micro- and nanotechnological realm. The original work in contact mechanics dates back to 1881 with the publication of the paper "On the contact of elastic solids" ("Ueber die Berührung fester elastischer Körper") by Heinrich Hertz. Hertz was attempting to understand how the optical properties of multiple, stacked lenses might change with the force holding them together. Hertzian contact stress refers to the localized stresses that develop as two curved surfaces come in contact and deform slightly under the imposed loads. This amount of deformation is dependent on the modulus of elasticity of the material in contact. It gives the contact stress as a function of the normal contact force, the radii of curvature of both bodies and the modulus of elasticity of both bodies. Hertzian contact stress forms the foundation for the equations for load bearing capabilities and fatigue life in bearings, gears, and any other bodies where two surfaces are in contact. History Classical contact mechanics is most notably associated with Heinrich Hertz. In 1882, Hertz solved the contact problem of two elastic bodies with curved surfaces. This still-relevant classical solution provides a foundation for modern problems in contact mechanics. For example, in mechanical engineering and tribology, Hertzian contact stress is a description of the stress within mating parts. The Hertzian contact stress usually refers to the stress close to the area of contact between two spheres of different radii. It was not until nearly one hundred years later that Johnson, Kendall, and Roberts found a similar solution for the case of adhesive contact. This theory was rejected by Boris Derjaguin and co-workers who proposed a different theory of adhesion in the 1970s. The Derjaguin model came to be known as the DMT (after Derjaguin, Muller and Toporov) model, and the Johnson et al. model came to be known as the JKR (after Johnson, Kendall and Roberts) model for adhesive elastic contact. This rejection proved to be instrumental in the development of the Tabor and later Maugis parameters that quantify which contact model (of the JKR and DMT models) represent adhesive contact better for specific materials. Further advancement in the field of contact mechanics in the mid-twentieth century may be attributed to names such as Bowden and Tabor. Bowden and Tabor were the first to emphasize the importance of surface roughness for bodies in contact. Through investigation of the surface roughness, the true contact area between friction partners is found to be less than the apparent contact area. Such understanding also drastically changed the direction of undertakings in tribology. The works of Bowden and Tabor yielded several theories in contact mechanics of rough surfaces. The contributions of Archard (1957) must also be mentioned in discussion of pioneering works in this field. Archard concluded that, even for rough elastic surfaces, the contact area is approximately proportional to the normal force. Further important insights along these lines were provided by Greenwood and Williamson (1966), Bush (1975), and Persson (2002). The main findings of these works were that the true contact surface in rough materials is generally proportional to the normal force, while the parameters of individual micro-contacts (i.e., pressure, size of the micro-contact) are only weakly dependent upon the load. Classical solutions for non-adhesive elastic contact The theory of contact between elastic bodies can be used to find contact areas and indentation depths for simple geometries. Some commonly used solutions are listed below. The theory used to compute these solutions is discussed later in the article. Solutions for multitude of other technically relevant shapes, e.g. the truncated cone, the worn sphere, rough profiles, hollow cylinders, etc. can be found in Contact between a sphere and a half-space An elastic sphere of radius R {\displaystyle R} indents an elastic half-space where total deformation is d {\displaystyle d} , causing a contact area of radius a = R d {\displaystyle a={\sqrt {Rd}}} The applied force F {\displaystyle F} is related to the displacement d {\displaystyle d} by F = 4 3 E ∗ R 1 2 d 3 2 {\displaystyle F={\frac {4}{3}}E^{*}R^{\frac {1}{2}}d^{\frac {3}{2}}} where 1 E ∗ = 1 − ν 1 2 .... Discover the Valentin L Popov Markus Hess popular books. Find the top 100 most popular Valentin L Popov Markus Hess books.
Best Seller Valentin L Popov Markus Hess Books of 2024
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A Christmas Carol
Charles DickensAn Apple Books Classic edition. It’s Christmas Eve in Victorian England. While some families don’t know where their next meal will come from, Ebenezer Scrooge sits in his large hom...
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The Target
Lexy TimmsWhen you seek revenge be sure to dig two graves… Revenge was the only thing I had going for me. It kept me awake at night and drove me into desperate situations in dive bars across...
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Whiskey Girl
Melissa BelleThey'll do anything for each other…except commit. Logan Wild isn’t just the hottest broncriding cowboy in Texas. He’s also my best friendwith benefits. And that’s all we’ll ev...
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The Honeymoon Homicide
J. R. Mathis & Susan MathisEnjoy this SmallTown Murder Mystery Featuring A Unique Sleuthing Couple I'm Father Tom Greer, a Catholic Priest in a smalltown parish who never expected this . . . When I came...
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The Art of War
Sun TzuAn Apple Books Classic edition. It’s believed that Sun Tzu wrote this Chinese military primer during the 5th century BChundreds of years before the Bible. The book’s 13 chapters ex...
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The Four Loves
C. S. LewisThe Four Loves summarizes four kinds of human loveaffection, friendship, erotic love, and the love of God. Masterful without being magisterial, this book's wise, gentle, candi...
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Silenced Girls
Roger Stelljes“ Wow wow wow!  Grips you in a choke hold and  does not let go … Oozes suspense and  bonechilling twists and turns .  Astonishing … One of those...
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Bewitching a Highlander
Roma CordonDefying all for the love of a bewitching lass. Breena MacRae, a healer from Skye with a touch of witchery in her blood, embarks on a dangerous search for her missing father. She ar...
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The Scarlet Letter
Nathaniel HawthorneAn Apple Books Classic edition. Hester Prynne lives in infamy. After committing adultery and bearing a child with a man whose name she refuses to divulge, the heroine of Nathaniel ...
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How to Choose a Guy in 10 Days
Lila MonroeThe only thing more hilarious than the movies is… real life?! Fall in love with the sizzling grumpysunshine romantic comedy perfect for fans of Sophie Kinsella and Ali Hazlewood! ...
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Think and Grow Rich
Greg Habstritt & Napoleon HillThink and Grow Rich is one of the most popular success book of alltime, having sold more than 60 million copies since it was first published more than 70...
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His Own Heaven
Jennie KewWinner of the 2021 Passionate Plume Award for BDSM Romance Finalist in the 2021 Stiletto Contest for Contemporary Romance He taught her to trust, she taught him to love. Lucy Bar...
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Dracula
Bram StokerAn Apple Books Classic edition. Few characters have seized readers’ imaginations quite like Count Dracula of Transylvania, the hero of Bram Stoker’s classic. The 1897 novel put vam...
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Law of Attraction
Jordan HollisHow to Finally Overcome the Hurdles of Manifesting Proven, effective and enjoyable ways to help you manifest faster… Right now, think of something that makes you successful. If you...
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The Three Little Pigs
Mark LeskyClassic fairy tales, legends and folk stories in short version without violence retold with lovely illustrations in simple language. Perfect for reading aloud to small chi...
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Dark Psychology and Manipulation
Margaret MorrisonTHE MENTAL MANIPULATOR WILL NO LONGER KEEP SECRETS FROM YOU! Are you fed up with the wool being pulled over your eyes?Are you prepared to stand up to those who believe they can man...
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Get Lucky
Lila MonroeFall for the hot and hilarious romcom spin on 'The Hangover', perfect for fans of Tessa Bailey, Ali Hazelwood, and Emily Henry! What happens when you wake up in a hotel s...
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The Odyssey
HomerAn Apple Books Classic edition. Homer’s eighthcentury epic poem is a companion to The Iliad . It tells the story of Odysseus, who journeys by ship for 10 years after the Trojan War...
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The Holy Bible - King James Version
King JamesHoly Bible King James Version Few Sample Paragraphs from The Holy Bible eBook, Genesis (OT) 1 Gen. 1 IN the beginning God created the heaven and the earth. 2 And the earth was with...
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Death at Hazel House
Betty Rowlands‘Riveting, can't put it down! I love this story… a wonderfully twisted tale of a crime that has more twists than I thought possible... fantastic.’ Goodreads Reviewer, 5 stars ...
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The Seduction Series Boxset
Roxy Sloane“Sensual, thrilling and wild!”   Discover the bestselling series in one collection: THE SEDUCTION, THE BARGAIN, and THE INVITATION. Perfect for fans of Ana Huang, Sierra S...
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School of Potential
W.J. MayUSA Today Bestselling author, W.J. May brings you a continuation of the international bestselling series, The Chronicles of Kerrigan! Come back and enjoy the famous characters, or ...
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A Bookshop to Die For
M.P. BlackDitching her fiancé at the altar, Alice Hartford bolts to her childhood hometown to reconnect with the last, happy remnant of her past: her mom's old bookstore. But the bookst...
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Holy Bible
The Church of Jesus Christ of Latter-day SaintsThe 2013 edition of the Holy Bible contains all of the study aids contained in the 1979 edition and includes revisions to the study aids, several new photos, updated maps, and adju...
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Escape, A New Life
David J AntocciTo save herself, she had to lose everything. Trapped in a tropical paradise with no memory of how she got there, Abby is thrust into a fight for her life. Hunted by a madman, and c...
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Peace on Earth
Maia RossCrime never takes a holiday. Why should Irma? Irma Abercrombie is an energetic retiree with a shadowy past, a mean right hook, and a profound love of Christmas. Surrounded by seaso...
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Inception of Gold
Lexy TimmsThings are not as bad as they seem. They are worse. Being the personal assistant to a narcissistic actress who just happens to own the key to my family's undoing isn't ex...
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Alpha
Sybil BartelBillionaire. Mercenary. Navy SEAL. The Teams trained me to be a killer. War taught me to be ruthless. Then an illfated mission proved I was human. Combat wounded, cut loose by the ...
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The Cupcake Cottage
Jean OramNHL player Maverick Blades could fall in love with anyone... But he had to fall for a woman who falls under the Bro Code as untouchablehis best friend’s beautiful ex, DaisyMae Ray....
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Pride and Prejudice
Jane AustenAn Apple Books Classic edition. Jane Austen’s beloved classic opens with this witty and very memorable line: “It is a truth universally acknowledged, that a single man in possessio...
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Saltwater Cove
Amelia AddlerSecond chances...and the secrets that sabotage them. At 48 years old, Margie Clifton never expected to be starting her life all over again. But when her brother gifts her a propert...
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Coffee Girl
Sophie SinclairMackenzie "Kiki" Forbes finds herself in a pickle. Either become her snarky sister's nanny, or move halfway across the country to work as assistanttothestylist of a ...
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The Stoic Mind
Addy Osmani & GoLimitlesssDiscover the timeless wisdom of Stoicism in a modern context with "The Stoic Mind," an enlightening visual guide by Addy Osmani and GoLimitlesss. This rich exploration co...
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Awaken Me
Jenna JacobHe was more than a ghost haunting my dreams…he was real. By day, I’m Julianna Garrett …a prim, proper accountant. By night, I’m tormented by dreams of an alpha, ambereyed Adonis wh...
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His Girl Next Door
Khardine GrayFrom USA Today Bestselling author Khardine Gray comes a sizzling hot single dad romance you won't want to miss. No strings attached fun with the ubergorgeous single d...
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Rogue Alpha
Kimber WhiteOne touch made her crave him. But the pull of fate could be the path to ruin. College student Laura Prince lands a plum internship deep in the Michigan wilderness. When she discove...
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Enemies With Benefits
Roxie NoirI don’t love him. I don’t even like him. I just want him. Eli Loveless was my nemesis from the first day of kindergarten until we graduated high school. Everything I did, he had to...
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Salvation
Meghan O'FlynnIf you like mouthy detectives, serial killers, and suspenseful mysteries that don't quit, this chilling and actionpacked hardboiled detective series has you covered! Try this ...
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Teased by Fire
Molly O'HareFrom USA Today bestselling author Molly O’Hare comes an enemiestolovers, older brother’s best friend, romantic comedy with a curvy, antisocial, supernaturalobsessed, allyearround h...
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Christmas in Sweetbriar Cove
Melody GraceCelebrate the holidays in Sweetbriar Cove with this festive romance collection, containing two sizzling smalltown holiday stories perfect for fans of Tessa Bailey, Sophie Kinsella...
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Finding Cinderella
Colleen Hoover#1 New York Times bestselling author of It Starts with Us and It Ends With Us writes a free novella about the search for happily ever after. A chance encounter in the dark leads ei...
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The Adventures of Sherlock Holmes
Arthur Conan DoyleAn Apple Books Classic You get not one, not two, but 25 gripping mysteries in Arthur Conan Doyle’s first of five collections of Sherlock Holmes short stories. Follow the brilliant ...
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Hot Off the Press
Lexy Timms"This is what really happened… reported by a free press, for a free people…" Wes Shaw leads a secret double life. As the secret owner of a billion dollar newspap...
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The Wonderful Wizard of Oz
L. Frank BaumAn Apple Books Classic edition. You’ve seen the iconic 1939 movie, but do you know about the talking field mice, the Winkies, and the Witch of the North that appear in the original...
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A Green Kind of Witch
Sierra CrossCinderella crossed with Mean Girls.   That's what Hazel's daily existence feels like. Born to a family of elegant yet shallow Beige Witches, seventeen y...
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The Icing on the Cake
Linda SeedShe’s a baker without a kitchen. He’s got a double oven to spare. It’s a recipe for success, until his mother starts stirring up trouble … Cassie Jordan has a sweet dream to open a...
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Dream Psychology
Sigmund FreudAn Apple Books Classic edition. Written by the founding father of psychoanalysis, Sigmund Freud’s 1899 book is the definitive text on learning to interpret dreams. Freud’s groundbr...
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Man In The Water
Jon HillAn attempted murder. A missing spouse. And an international conspiracy that could change the world. Jack Green has always been skeptical of socalled facts. Though he's forced ...
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Just Me
Lexy TimmsWe all need somewhere where we feel safe… After leaving her abusive husband, Katherine Marshall is out on her own for the first time. She's hopped from city to city to avoid t...
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Meditations
Emperor of Rome Marcus AureliusMeditations is a series of personal writings by Marcus Aurelius, Roman Emperor 161–180 CE, setting forth his ideas on Stoic philosophy.