| 1. |
- Borg, Rikard, 1962-, et al.
(author)
-
Simulating DCB, ENF and MMB experiments using shell elements and a cohesive zone model
- 2004
-
In: Composites Science And Technology. - 0266-3538 .- 1879-1050. ; 64:2, s. 269-278
-
Journal article (peer-reviewed)abstract
- A delamination model for shell elements is presented. It consists of an adhesive penalty contact formulation for initially tying shells together and a cohesive zone model for degrading the adhesive forces. An adhesive contact used between shell elements has to account for the thickness offset, such that the rotational degrees of freedom in the shell elements are included in the algorithm. This is considered in the present contact model and the complete delamination model is implemented in the explicit Finite Element code LS-DYNA. By preventing delamination growth the delamination model can be turned into a tied contact. As such it is used in two FE-models, where plates are bonded together and subjected to various loads. The adhesive penalty contact performs well. The complete delamination is validated by simulating the Double Cantilever Beam, End-Notch Flexural and Mixed Mode Bending setups, and the results are shown to be in agreement with experimental data.
|
|
| 2. |
- Borg, Rikard, 1962-, et al.
(author)
-
Simulation of delamination in fiber composites with a discrete cohesive failure model
- 2001
-
In: Composites Science And Technology. - 0266-3538 .- 1879-1050. ; 61:5
-
Other publication (pop. science, debate, etc.)abstract
- Delamination initiation and growth are analyzed by using a discrete cohesive crack model. The model is derived by postulating the existence of a maximum load surface which limits the adhesive forces in the process zone of the crack. The size of the maximum load surface is made dependent on the amount of dissipated crack opening work such that the maximum load surface shrinks to zero as a predefined amount of work is consumed. Mode I, II, III loading or any combined loading is possible. The delamination model is implemented in the explicit finite-element code LS-DYNA and simulation results are found to be in agreement with experimental results. ⌐ 2001 Elsevier Science Ltd. All rights reserved.
|
|
| 3. |
- Borg, Rikard, 1962-, et al.
(author)
-
Simulation of low velocity impact on fiber laminates using a cohesive zone based delamination model
- 2004
-
In: Composites Science And Technology. - 0266-3538 .- 1879-1050. ; 64:2, s. 279-288
-
Journal article (peer-reviewed)abstract
- An existing delamination model is further developed for use in transverse impact simulations. An algorithm is developed making it possible to determine the propagation direction of the delamination front. Using this it is possible to determine relative orientation of the delamination front with respect to the fibers above and below the interface. In a qualitative evaluation it is shown that the present delamination model can be used for modeling delamination initiation and growth in transverse impact simulations.
|
|
| 4. |
|
|
| 5. |
- Domeij Bäckryd, Rebecka, 1978-, et al.
(author)
-
Multidisciplinary design optimisation methods for automotive structures
- 2017
-
In: International Journal of Automotive and Mechanical Engineering. - Pekan, Malaysia : Universiti Malaysia Pahang Publishing. - 2229-8649 .- 2180-1606. ; 14:1, s. 4050-4067
-
Journal article (peer-reviewed)abstract
- Multidisciplinary design optimisation (MDO) can be used as an effective tool to improve the design of automotive structures. Large-scale MDO problems typically involve several groups who must work concurrently and autonomously in order to make the solution process efficient. In this article, the formulations of existing MDO methods are compared and their suitability is assessed in relation to the characteristics of automotive structural applications. Both multi-level and single-level optimisation methods are considered. Multi-level optimisation methods distribute the design process but are complex. When optimising automotive structures, metamodels are often required to relieve the computational burden of detailed simulation models. The metamodels can be created by individual groups prior to the optimisation process, and thus offer a way of distributing work. Therefore, it is concluded that a single-level method in combination with meta-models is the most straightforward way of implementing MDO into the development of automotive structures. If the benefits of multi-level optimisation methods, in a special case, are considered to compensate for their drawbacks, analytical target cascading has a number of advantages over collaborative optimisation, but both methods are possible choices.
|
|
| 6. |
- Fjällström, Per-Olof, 1954-, et al.
(author)
-
Evaluation of Range Searching Methods for Contact Searching in Mechanical Engineering
- 1998
-
In: International Journal of Computational Geometry & Applications. - : World Scientific Publishing Co. Pte. Ltd.. - 0218-1959. ; 8:1, s. 67-83
-
Journal article (peer-reviewed)abstract
- Contact searching is an important and time-consuming part of computer simulation of certain deformation processes. Contact searching can be facilitated by orthogonal range searching. We have experimentally evaluated four methods for orthogonal range searching: the projection method, the cell method, the k-d tree method, and the range tree method. The results of our experiments indicate that two of these methods, the cell and k-d tree methods, have practical significance. The cell method is in most cases faster than the k-d tree method.
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
|
|
