tecosim project: automatic bolt generator for crash simulations
TRANSCRIPT
| |
Development of an automatic bolt generator for crash simulations in ABAQUS
Abstract of project results
| |
Bolt connections in vehicle construction
July 2016 Development of an automatic bolt generator for crash simulations in ABAQUS 2
1. INITIAL SITUATION
§ Along with welded joints, bolt connections are the most frequently used means of fastening
§ A medium-class vehicle contains about 250 safety-relevant bolt connections
§ In crash simulations, bolt connections are generally modeled as simplified analogous models (Beams or Connectors)
§ Requirements for more exact prediction capacity in complete vehicle simulations and occupant safety are increasing
§ More efficient modelling at a favourable cost is required
Bol
t fu
ncti
ons
| |
Main objectives
July 2016 Development of an automatic bolt generator for crash simulations in ABAQUS 3
2. TASK
§ Programming of a ANSA-GUI (graphical user interface) to generate solid bolts automatically § Produce and validate material cards for bolts in different property classes
The breaking force should match theoretical values or test data as best as possible - Bolt sizes studied: M8, M10, M12, M14, M16, M18 - Property classes studied: 6.8, 8.8, 10.9, 12.9 - Type of thread pitch: metric - On material properties: Elastic deformation
Plastic deformation Necking until fracture - Criteria for assessing the bolt model quality: ultimate tensile strength, ultimate shear strength
| |
Possible bolt variants
July 2016 Development of an automatic bolt generator for crash simulations in ABAQUS 4
3. PROJECT DESCRIPTION / IMPLEMENTATION
Four variants for bolt modelling: (A) Bolt with nut and shank
(B) Bolt with nut, but no shank (C) Bolt with no nut, but with shank (D) Bolt with no nut and no shank
| |
GUI for bolts with nuts
July 2016 Development of an automatic bolt generator for crash simulations in ABAQUS 5
3. PROJECT DESCRIPTION / IMPLEMENTATION
§ Section 1: selection of bolt size, strength class,
type of bolt connection
§ Section 2: definition of bolt geometry
§ Section 3: parameters for pre-stressing
§ Section 4: generate and position bolts (bolt is automatically numbered, contacts with flange generated, prepared for output as seperate include)
| |
Result
July 2016 Development of an automatic bolt generator for crash simulations in ABAQUS 6
4. RESULTS AND PROSPECTS
§ A tool has been developed to generate high-quality models for crash load cases more easily and more quickly than before
§ The bolts, including their pre-loading calculation, can now be generated and positioned easily on a simple GUI (graphical user interface) with just three clicks
§ The bolts are pre-loaded using a connector, so that a realistic grip is achieved
§ A material model whith failure criteria was also generated and validated which takes many standard bolt sizes and strength classes into account
§ The model is based on theoretical values taken from bolt tables
§ The bolts show a comparable, realistic result in test load cases; no larger deviations occur until higher deformation rates are reached
| |
Contact
July 2016 Development of an automatic bolt generator for crash simulations in ABAQUS 7
TECOSIM Technische Simulation GmbH Wolfgang Woost General Manager Wilhelm-Wagenfeld-Str. 3 D-80807 Munich
Tel +49 (0)89 552 679-17 Fax +49 (0)89 552 679-22 Mail [email protected] www.tecosim.com