Introduction and evaluation of a damping determination method based on the short-term fourier transform and resampling (stfr)

In the present paper, a frequency domain method for damping determination is presented. The described method is especially developed for low damped systems with well separated eigenfrequencies. Using the Short-Term Fourier transform and Resampling (STFR) of the signal, decay curves of several mode shapes can be identified and amplitude-dependent damping values can be calculated. Additionally, two common methods for damping determination are explained briefly. Finally, the quality of the introduced method is evaluated comparing the variances of the identified damping values by means of different methods. In this context, the damping for beams clamped in a suspended way is analyzed. Stainless steel is used as the specimen material

Analysis of an experimental setup for structural damping identification

In the present paper, an experimental setup for structural damping determination arising from energy dissipations within the material is presented. The experimental setup is developed in such a way that all unintended damping sources are eliminated. In this connection, priority is also given to the reproducibility of the experimental data. In addition, a vacuum chamber is developed to reduce the damping arising from the interaction with the surrounding medium. Furthermore, beam-shaped specimens are clamped in a suspended way, using screws with an apex to fix the specimens in their nodes of vibration. Then, the influence of test rig specific parameters on the damping value is analyzed. In this context, an ideal setup of the test rig is identified to measure structural damping values arising from dissipations within the material. Finally, a common model for material damping description is parameterized using the experimental data

Utilization of Interdisciplinary Tumor Boards for Sarcoma Care in Germany: Results from the PROSa Study

Background: Data on institutional structures of sarcoma care in Germany are scarce. The utilization of an interdisciplinary tumor board (IDTB) is an essential part of modern cancer care. We investigated to which extent and when IDTB are used in sarcoma care. We hypothesized that IDTB before treatment initiation were used more often at certified cancer centers and at high-volume centers and that IDTB utilization increased over time. Methods: From 2017 to 2020 we conducted a prospective cohort study, undertaking major efforts to include the whole spectrum of sarcoma treatment facilities. To analyze potential predictors of IDTB utilization, we calculated multivariable logistic regressions. Results: Patients and survivors (n = 1,309) from 39 study centers (22 tertiary referral hospitals, 9 other hospitals, and 8 office-based practices) participated; 88.3% of the patients were discussed at some stage of their disease in an IDTB (56.1% before treatment, 78% after therapy, and 85.9% in metastatic disease). Hypotheses were confirmed regarding the utilization of IDTB in certified cancer centers (vs. all others: OR = 5.39; 95% CI 3.28-8.85) and the time of diagnosis (2018/2019 vs. until 2013: OR = 4.95; 95% CI 2.67-9.21). Conclusion:Our study adds to the evidence regarding the institutional structures of sarcoma care in Germany. Utilization of a tumor board before therapy seems to be in an implementation process that is making progress but is far from complete. Certification is a possible tool to accelerate this development