Dr. Han Hu: "We developed an Isogeometric analysis numerical framework using a complete variational approach to address nonlinear flexoelectric problems. This framework considers the piezoelectric effect, flexoelectric effect, and Maxwell stress effect of the dielectric. To illustrate its capabilities, we simulated a cantilever beam subjected to a constant torque at the right end, showcasing the direct flexoelectric effect where deformation generates electricity across the beam."
![](https://www.cotoflexi.uni-hannover.de/fileadmin/_processed_/a/8/csm_converse_effect_animation_c621ebc69b.gif)
![](https://www.cotoflexi.uni-hannover.de/fileadmin/_processed_/a/8/csm_converse_effect_animation_9043c61658.gif)
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Fig1. Animation of a beam deformed due to electric loading. The colormap indicates the Von-mises stress distribution. Model parameters: thickness H = 1 μm, length L = 20H, Young’s modulus Y = 1GPa, Poisson’s ratio ν = 0.3, dielectric constant ϵ = 0.092 nC/Vm, characteristic length ls = 0, μL = 0 and μT = 10 nC/m, applied electric potential Φ0 = 1.469 kV.
![](https://www.cotoflexi.uni-hannover.de/fileadmin/_processed_/7/f/csm_direct_effect_animation_46017a5c6c.gif)
![](https://www.cotoflexi.uni-hannover.de/fileadmin/_processed_/7/f/csm_direct_effect_animation_01f6831aa9.gif)
![](https://www.cotoflexi.uni-hannover.de/fileadmin/cotoflexi/photo/direct_effect_animation.gif)
Fig 4. Animation of a beam deformed due to mechanical loading. The colormap indicates the electric potential distribution. Model parameters: thickness H = 1 μm, length L = 20H, Young’s modulus Y = 1GPa, Poisson’s ratio ν = 0.3, dielectric constant ϵ = 0.092 nC/Vm, characteristic length ls = 0, μL = 0 and μT = 10 nC/m, applied moment M0 = 30 Nm.
Fig 5. Schematic of a cantilever beam with open circuit setting.
Additionally, we demonstrated the converse flexoelectric effect by applying a prescribed electric potential to the top surface of the beam, causing significant deformation and warping into a circular shape.
![](https://www.cotoflexi.uni-hannover.de/fileadmin/_processed_/f/b/csm_converse_effect_setting_d76cdf4d15.png)
![](https://www.cotoflexi.uni-hannover.de/fileadmin/_processed_/f/b/csm_converse_effect_setting_ef43ad0f7a.png)
![](https://www.cotoflexi.uni-hannover.de/fileadmin/_processed_/f/b/csm_converse_effect_setting_b12dcf0d44.png)
Fig 2. Schematic of a cantilever beam with closed circuit setting.
![](https://www.cotoflexi.uni-hannover.de/fileadmin/_processed_/2/a/csm_converse_result_ffda84715e.jpg)
![](https://www.cotoflexi.uni-hannover.de/fileadmin/_processed_/2/a/csm_converse_result_03b5c5e803.jpg)
![](https://www.cotoflexi.uni-hannover.de/fileadmin/_processed_/2/a/csm_converse_result_a7db78e25b.jpg)
Fig 3. Von-mises stress distribution of the deformed cantilever beam at final configuration.
![](https://www.cotoflexi.uni-hannover.de/fileadmin/_processed_/3/c/csm_direct_effect_setting_48485be648.png)
![](https://www.cotoflexi.uni-hannover.de/fileadmin/_processed_/3/c/csm_direct_effect_setting_8194277d51.png)
![](https://www.cotoflexi.uni-hannover.de/fileadmin/_processed_/3/c/csm_direct_effect_setting_f8bc0ad1fb.png)
Fig 5. Schematic of a cantilever beam with open circuit setting.
![](https://www.cotoflexi.uni-hannover.de/fileadmin/_processed_/6/2/csm_direct_result_adf9112102.jpg)
![](https://www.cotoflexi.uni-hannover.de/fileadmin/_processed_/6/2/csm_direct_result_91d6943fc6.jpg)
![](https://www.cotoflexi.uni-hannover.de/fileadmin/_processed_/6/2/csm_direct_result_30e17505b4.jpg)
Fig 6. Electric potential distribution of the deformed cantilever beam at final configuration.